CompareInfo.LastIndexOf Metodo

Riferimento

Definizione

Spazio dei nomi:: System.Globalization

Assembly:: System.Globalization.dll

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Importante

Alcune informazioni sono relative alla release non definitiva del prodotto, che potrebbe subire modifiche significative prima della release definitiva. Microsoft non riconosce alcuna garanzia, espressa o implicita, in merito alle informazioni qui fornite.

Restituisce l'indice in base zero dell'ultima occorrenza di un valore all'interno di una stringa o di una parte di essa.

Overload

LastIndexOf(String, String, Int32, Int32, CompareOptions)	Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine che contiene il numero specificato di elementi e termina in corrispondenza dell'indice specificato, usando il valore CompareOptions specificato.
LastIndexOf(String, Char, Int32, Int32, CompareOptions)	Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine che contiene il numero specificato di elementi e termina in corrispondenza dell'indice specificato, usando il valore CompareOptions specificato.
LastIndexOf(String, String, Int32, Int32)	Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine che contiene il numero specificato di elementi e termina in corrispondenza dell'indice specificato.
LastIndexOf(String, String, Int32, CompareOptions)	Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza nella sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato, usando il valore CompareOptions specificato.
LastIndexOf(String, Char, Int32, Int32)	Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine che contiene il numero specificato di elementi e termina in corrispondenza dell'indice specificato.
LastIndexOf(String, Char, Int32, CompareOptions)	Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato, usando il valore CompareOptions specificato.
LastIndexOf(ReadOnlySpan<Char>, ReadOnlySpan<Char>, CompareOptions, Int32)	Cerca l'ultima occorrenza di una sottostringa all'interno di una stringa di origine.
LastIndexOf(String, Char)	Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine.
LastIndexOf(String, String, CompareOptions)	Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine usando il valore CompareOptions specificato.
LastIndexOf(String, Char, Int32)	Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato.
LastIndexOf(String, Char, CompareOptions)	Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine usando il valore CompareOptions specificato.
LastIndexOf(ReadOnlySpan<Char>, Rune, CompareOptions)	Cerca l'ultima occorrenza di un oggetto Rune all'interno dell'intervallo di caratteri di sola lettura specificato.
LastIndexOf(ReadOnlySpan<Char>, ReadOnlySpan<Char>, CompareOptions)	Cerca l'ultima occorrenza di una sottostringa all'interno dell'intervallo di caratteri di sola lettura specificato.
LastIndexOf(String, String)	Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine.
LastIndexOf(String, String, Int32)	Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato.

LastIndexOf(String, String, Int32, Int32, CompareOptions)

Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine che contiene il numero specificato di elementi e termina in corrispondenza dell'indice specificato, usando il valore CompareOptions specificato.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, int count, System::Globalization::CompareOptions options);

public:
 int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, int count, System::Globalization::CompareOptions options);

public virtual int LastIndexOf (string source, string value, int startIndex, int count, System.Globalization.CompareOptions options);

public int LastIndexOf (string source, string value, int startIndex, int count, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * string * int * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * string * int * int * System.Globalization.CompareOptions -> int

member this.LastIndexOf : string * string * int * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer, count As Integer, options As CompareOptions) As Integer

Public Function LastIndexOf (source As String, value As String, startIndex As Integer, count As Integer, options As CompareOptions) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: String

Stringa da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

count: Int32

Numero di elementi nella sezione in cui eseguire la ricerca.

options: CompareOptions

Valore che definisce la modalità di confronto di source e value. options è il valore di enumerazione Ordinal o la combinazione bit per bit di uno o più dei seguenti valori: IgnoreCase, IgnoreSymbols, IgnoreNonSpace, IgnoreWidth e IgnoreKanaType.

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value, se presente, all'interno della sezione di source che contiene il numero di elementi specificato da count e termina in corrispondenza di startIndex, usando le opzioni di confronto specificate; in caso contrario, -1. Restituisce startIndex se value è un carattere che è possibile ignorare.

Eccezioni

ArgumentNullException

source è null.

-oppure-

value è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

-oppure-

count è minore di zero.

-oppure-

startIndex e count non specificano una sezione valida in source.

ArgumentException

options contiene un valore di CompareOptions non valido.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una parte di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 8;
   
   // iL is the length of the substring.
   int iL = 18;
   
   // myT1 and myT2 are the strings used for padding.
   String^ myT1 = gcnew String( '-',iS );
   String^ myT2;
   
   // Searches for the ligature Ã†.
   String^ myStr = "Is AE or ae the same as Ã† or Ã¦?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

Original      : Is AE or ae the same as Ã† or Ã¦?
No options    : -------- ae the same as Ã† -----
           AE :                         b
           ae :          b
            Ã† :                         b
            Ã¦ :          b
Ordinal       : -------- ae the same as Ã† -----
           AE :
           ae :          b
            Ã† :                         b
            Ã¦ :
IgnoreCase    : -------- ae the same as Ã† -----
           AE :          f              l
           ae :          f              l
            Ã† :          f              l
            Ã¦ :          f              l

Original      : Is U" or u" the same as Ãœ or Ã¼?
No options    : -------- u" the same as Ãœ -----
           U" :                         b
           u" :          b
            Ãœ :                         b
            Ã¼ :          b
Ordinal       : -------- u" the same as Ãœ -----
           U" :
           u" :          b
            Ãœ :                         b
            Ã¼ :
IgnoreCase    : -------- u" the same as Ãœ -----
           U" :          f              l
           u" :          f              l
            Ãœ :          f              l
            Ã¼ :          f              l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Commenti

La stringa di origine viene eseguita una ricerca all'indietro a partire da startIndex e termina con startIndex - count + 1.

Il CompareOptions.StringSort valore non è valido per questo metodo.

Se options non include il Ordinal valore, questo overload esegue una ricerca sensibile alle impostazioni cultura. Un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), può essere considerato equivalente a qualsiasi occorrenza dei componenti del carattere nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Se options include il Ordinal valore, questo overload esegue una ricerca ordinale (senza distinzione tra impostazioni cultura), in cui vengono confrontati i valori Unicode.

Nota

Quando possibile, è necessario chiamare metodi di confronto tra stringhe con un parametro di tipo CompareOptions per specificare il tipo di confronto previsto. Come regola generale, usare le opzioni linguistiche (usando le impostazioni cultura correnti) per confrontare le stringhe visualizzate nell'interfaccia utente e specificare CompareOptions.Ordinal o CompareOptions.OrdinalIgnoreCase per i confronti di sicurezza.

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che sono caratteri non considerati durante l'esecuzione di un ordinamento linguistico o sensibile alle impostazioni cultura. In una ricerca dipendente dalle impostazioni cultura (ovvero se options non è Ordinal o OrdinalIgnoreCase), se value contiene un carattere ignorable, il risultato è equivalente alla ricerca con il carattere rimosso. Se value è costituito solo da uno o più caratteri ignorabili, il LastIndexOf(String, String, Int32, Int32, CompareOptions) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca.

Nell'esempio seguente, il LastIndexOf(String, String, Int32, Int32, CompareOptions) metodo viene usato per trovare la posizione di un trattino morbido (U+00AD) seguito da un "m" in tutti i caratteri, ma la prima posizione del carattere prima della "m" finale in due stringhe. Solo una delle stringhe contiene la sottostringa richiesta. In entrambi i casi, poiché il segno meno facoltativo è un carattere ignorabile, il metodo restituisce l'indice di "m" nella stringa quando viene eseguito un confronto dipendente dalle impostazioni cultura. Quando esegue un confronto ordinale, tuttavia, trova la sottostringa solo nella prima stringa. Si noti che nel caso della prima stringa, che include il trattino morbido seguito da un "m", il metodo non restituisce l'indice del trattino morbido, ma restituisce invece l'indice di "m" quando esegue un confronto con distinzione tra impostazioni cultura. Il metodo restituisce l'indice del segno meno facoltativo nella prima stringa solo quando esegue un confronto ordinale.

Imports System.Globalization

Public Module Example
   Public Sub Main()
      Dim ci As CompareInfo = CultureInfo.CurrentCulture.CompareInfo

      Dim searchString As String = ChrW(&h00AD) + "m"
      Dim s1 As String = "ani" + ChrW(&h00AD) + "m" 
      Dim s2 As String = "animal"
      Dim position As Integer

      position = ci.LastIndexOf(s1, "m"c)
      If position >= 1 Then
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, position, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s1, searchString, position, position, CompareOptions.Ordinal))
      End If      
      
      position = ci.LastIndexOf(s2, "m"c)
      If position >= 1 Then 
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, position, CompareOptions.None))
         Console.WriteLine(ci.LastIndexOf(s2, searchString, position, position, CompareOptions.Ordinal))
      End If
   End Sub
End Module
' The example displays the following output:
'       4
'       3
'       3
'       -1

Vedi anche

Si applica a

LastIndexOf(String, Char, Int32, Int32, CompareOptions)

Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine che contiene il numero specificato di elementi e termina in corrispondenza dell'indice specificato, usando il valore CompareOptions specificato.

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex, int count, System::Globalization::CompareOptions options);

public:
 int LastIndexOf(System::String ^ source, char value, int startIndex, int count, System::Globalization::CompareOptions options);

public virtual int LastIndexOf (string source, char value, int startIndex, int count, System.Globalization.CompareOptions options);

public int LastIndexOf (string source, char value, int startIndex, int count, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * char * int * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * char * int * int * System.Globalization.CompareOptions -> int

member this.LastIndexOf : string * char * int * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer, count As Integer, options As CompareOptions) As Integer

Public Function LastIndexOf (source As String, value As Char, startIndex As Integer, count As Integer, options As CompareOptions) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: Char

Carattere da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

count: Int32

Numero di elementi nella sezione in cui eseguire la ricerca.

options: CompareOptions

Restituisce

Int32

Eccezioni

ArgumentNullException

source è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

-oppure-

count è minore di zero.

-oppure-

startIndex e count non specificano una sezione valida in source.

ArgumentException

options contiene un valore di CompareOptions non valido.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una parte di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 8;
   
   // iL is the length of the substring.
   int iL = 18;
   
   // myT1 and myT2 are the strings used for padding.
   String^ myT1 = gcnew String( '-',iS );
   String^ myT2;
   
   // Searches for the ligature Ã†.
   String^ myStr = "Is AE or ae the same as Ã† or Ã¦?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

Original      : Is AE or ae the same as Ã† or Ã¦?
No options    : -------- ae the same as Ã† -----
           AE :                         b
           ae :          b
            Ã† :                         b
            Ã¦ :          b
Ordinal       : -------- ae the same as Ã† -----
           AE :
           ae :          b
            Ã† :                         b
            Ã¦ :
IgnoreCase    : -------- ae the same as Ã† -----
           AE :          f              l
           ae :          f              l
            Ã† :          f              l
            Ã¦ :          f              l

Original      : Is U" or u" the same as Ãœ or Ã¼?
No options    : -------- u" the same as Ãœ -----
           U" :                         b
           u" :          b
            Ãœ :                         b
            Ã¼ :          b
Ordinal       : -------- u" the same as Ãœ -----
           U" :
           u" :          b
            Ãœ :                         b
            Ã¼ :
IgnoreCase    : -------- u" the same as Ãœ -----
           U" :          f              l
           u" :          f              l
            Ãœ :          f              l
            Ã¼ :          f              l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Commenti

La stringa di origine viene eseguita una ricerca indietro a startIndex partire da e termina a startIndex - count + 1.

Il CompareOptions.StringSort valore non è valido per questo metodo.

Se options non include il valore, questo overload esegue una ricerca sensibile alle Ordinal impostazioni cultura. Se il carattere è un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), potrebbe essere considerata equivalente a qualsiasi occorrenza dei relativi componenti nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Se options include il Ordinal valore, questo overload esegue una ricerca ordinale (cultura-insensibile). Un carattere viene considerato equivalente a un altro carattere solo se i valori Unicode sono uguali. Gli overload di String.LastIndexOf tale ricerca di un carattere eseguono una ricerca ordinale, mentre quelli che cercano una stringa eseguono una ricerca sensibile alle impostazioni cultura.

Nota

Quando possibile, è necessario chiamare metodi di confronto stringa con un parametro di tipo CompareOptions per specificare il tipo di confronto previsto. Come regola generale, usare le opzioni linguistiche (usando le impostazioni cultura correnti) per confrontare le stringhe visualizzate nell'interfaccia utente e specificare CompareOptions.Ordinal o CompareOptions.OrdinalIgnoreCase per i confronti di sicurezza.

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che sono caratteri non considerati durante l'esecuzione di un ordinamento linguistico o sensibile alle impostazioni cultura. In una ricerca sensibile alle impostazioni cultura, se value è un carattere ignorabile, il risultato equivale alla ricerca con tale carattere rimosso. In questo caso, il LastIndexOf(String, Char, Int32, Int32, CompareOptions) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca. Nell'esempio seguente il LastIndexOf(String, Char, Int32, Int32, CompareOptions) metodo viene usato per trovare un trattino morbido (U+00AD) che precede l'ultimo "m" in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In entrambi i casi, poiché il trattino morbido è un carattere ignorabile, una ricerca sensibile alle impostazioni cultura restituisce la posizione di indice di "m", ovvero il valore di startIndex. Una ricerca ordinale, tuttavia, trova correttamente il trattino morbido in una stringa e segnala che è assente dalla seconda stringa.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      int position = 0;

      // Find the index of the soft hyphen using culture-sensitive comparison.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position,
                           position + 1, CompareOptions.IgnoreCase));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position,
                           position + 1, CompareOptions.IgnoreCase));

      // Find the index of the soft hyphen using ordinal comparison.
      position = ci.LastIndexOf(s1, 'm');
      Console.WriteLine("'m' at position {0}", position, CompareOptions.Ordinal);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', position,
                           position + 1, CompareOptions.Ordinal));

      position = ci.LastIndexOf(s2, 'm');
      Console.WriteLine("'m' at position {0}", position, CompareOptions.Ordinal);
      if (position >= 0)
         Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', position,
                           position + 1, CompareOptions.Ordinal));
   }
}
// The example displays the following output:
//       'm' at position 4
//       4
//       'm' at position 3
//       3
//       'm' at position 4
//       3
//       'm' at position 3
//       -1

Vedi anche

Si applica a

LastIndexOf(String, String, Int32, Int32)

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, int count);

public:
 int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, int count);

public virtual int LastIndexOf (string source, string value, int startIndex, int count);

public int LastIndexOf (string source, string value, int startIndex, int count);

abstract member LastIndexOf : string * string * int * int -> int
override this.LastIndexOf : string * string * int * int -> int

member this.LastIndexOf : string * string * int * int -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer, count As Integer) As Integer

Public Function LastIndexOf (source As String, value As String, startIndex As Integer, count As Integer) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: String

Stringa da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

count: Int32

Numero di elementi nella sezione in cui eseguire la ricerca.

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value, se presente, all'interno della sezione di source che contiene il numero di elementi specificato da count e che termina in corrispondenza di startIndex; in caso contrario, -1. Restituisce startIndex se value è un carattere che è possibile ignorare.

Eccezioni

ArgumentNullException

source è null.

-oppure-

value è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

-oppure-

count è minore di zero.

-oppure-

startIndex e count non specificano una sezione valida in source.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una parte di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 8;
   
   // iL is the length of the substring.
   int iL = 18;
   
   // myT1 and myT2 are the strings used for padding.
   String^ myT1 = gcnew String( '-',iS );
   String^ myT2;
   
   // Searches for the ligature Ã†.
   String^ myStr = "Is AE or ae the same as Ã† or Ã¦?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

Original      : Is AE or ae the same as Ã† or Ã¦?
No options    : -------- ae the same as Ã† -----
           AE :                         b
           ae :          b
            Ã† :                         b
            Ã¦ :          b
Ordinal       : -------- ae the same as Ã† -----
           AE :
           ae :          b
            Ã† :                         b
            Ã¦ :
IgnoreCase    : -------- ae the same as Ã† -----
           AE :          f              l
           ae :          f              l
            Ã† :          f              l
            Ã¦ :          f              l

Original      : Is U" or u" the same as Ãœ or Ã¼?
No options    : -------- u" the same as Ãœ -----
           U" :                         b
           u" :          b
            Ãœ :                         b
            Ã¼ :          b
Ordinal       : -------- u" the same as Ãœ -----
           U" :
           u" :          b
            Ãœ :                         b
            Ã¼ :
IgnoreCase    : -------- u" the same as Ãœ -----
           U" :          f              l
           u" :          f              l
            Ãœ :          f              l
            Ã¼ :          f              l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Commenti

La stringa di origine viene eseguita una ricerca indietro a startIndex partire da e termina a startIndex - count + 1.

Questo overload esegue una ricerca sensibile alle impostazioni cultura. Un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), può essere considerata equivalente a qualsiasi occorrenza dei componenti del carattere nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Per eseguire una ricerca ordinale (cultura-insensibile), in cui vengono confrontati i valori Unicode, è necessario chiamare uno degli overload con un parametro di tipo CompareOptions e usare il Ordinal valore.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che non vengono considerati quando si esegue un ordinamento linguistico o con distinzione tra impostazioni cultura. In una ricerca dipendente dalle impostazioni cultura, se value contiene un carattere ignorabile, il risultato è equivalente alla ricerca con il carattere rimosso. Se value è costituito solo da uno o più caratteri ignorabili, il LastIndexOf(String, String, Int32, Int32) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca.

Nell'esempio seguente viene usato il LastIndexOf(String, String, Int32, Int32) metodo per trovare la posizione di un trattino morbido (U+00AD) seguito da un "m" nei tre caratteri che precedono l'ultimo "m" di due stringhe. Solo una delle stringhe contiene la sottostringa richiesta. In entrambi i casi, poiché il segno meno facoltativo è un carattere ignorabile, il metodo restituisce l'indice di "m" nella stringa quando viene eseguito un confronto dipendente dalle impostazioni cultura. Si noti che nel caso della prima stringa, che include il segno meno facoltativo seguito da una "m", il metodo non restituisce l'indice del segno meno facoltativo, ma l'indice di "m".

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable16.cs" id="Snippet17": code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable16.vb" id="Snippet17":::

Vedi anche

IndexOf(String, Char)

Si applica a

LastIndexOf(String, String, Int32, CompareOptions)

Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza nella sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato, usando il valore CompareOptions specificato.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, System::Globalization::CompareOptions options);

public:
 int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex, System::Globalization::CompareOptions options);

public virtual int LastIndexOf (string source, string value, int startIndex, System.Globalization.CompareOptions options);

public int LastIndexOf (string source, string value, int startIndex, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * string * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * string * int * System.Globalization.CompareOptions -> int

member this.LastIndexOf : string * string * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer, options As CompareOptions) As Integer

Public Function LastIndexOf (source As String, value As String, startIndex As Integer, options As CompareOptions) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: String

Stringa da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

options: CompareOptions

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value, se presente, all'interno della sezione di source compresa tra l'inizio di source e startIndex, usando le opzioni di confronto specificate; in caso contrario, -1. Restituisce startIndex se value è un carattere che è possibile ignorare.

Eccezioni

ArgumentNullException

source è null.

-oppure-

value è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

ArgumentException

options contiene un valore di CompareOptions non valido.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una parte di una stringa. Si noti che IndexOf e LastIndexOf si esegue la ricerca in parti diverse della stringa, anche con lo stesso startIndex parametro.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 20;
   
   // myT1 is the string used for padding.
   String^ myT1;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Commenti

La stringa di origine viene eseguita una ricerca indietro a startIndex partire da e termina all'inizio della stringa.

Il CompareOptions.StringSort valore non è valido per questo metodo.

Se options non include il valore, questo overload esegue una ricerca sensibile alle Ordinal impostazioni cultura. Un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), può essere considerata equivalente a qualsiasi occorrenza dei componenti del carattere nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Se options include il Ordinal valore, questo overload esegue una ricerca ordinale (cultura-insensibile), in cui vengono confrontati i valori Unicode.

Nota

Note per i chiamanti

Nell'esempio seguente viene usato il LastIndexOf(String, String, Int32, CompareOptions) metodo per trovare la posizione di un trattino morbido (U+00AD) seguito da un "m", a partire dalla "m" finale in due stringhe. Solo una delle stringhe contiene la sottostringa richiesta. In entrambi i casi, poiché il segno meno facoltativo è un carattere ignorabile, il metodo restituisce l'indice di "m" nella stringa quando viene eseguito un confronto dipendente dalle impostazioni cultura. Si noti che nel caso della prima stringa, che include il segno meno facoltativo seguito da una "m", il metodo non restituisce l'indice del segno meno facoltativo, ma l'indice di "m". Il metodo restituisce l'indice del segno meno facoltativo nella prima stringa solo quando esegue un confronto ordinale.

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable14.cs" id="Snippet15": code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable14.vb" id="Snippet15"::

Vedi anche

Si applica a

LastIndexOf(String, Char, Int32, Int32)

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex, int count);

public:
 int LastIndexOf(System::String ^ source, char value, int startIndex, int count);

public virtual int LastIndexOf (string source, char value, int startIndex, int count);

public int LastIndexOf (string source, char value, int startIndex, int count);

abstract member LastIndexOf : string * char * int * int -> int
override this.LastIndexOf : string * char * int * int -> int

member this.LastIndexOf : string * char * int * int -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer, count As Integer) As Integer

Public Function LastIndexOf (source As String, value As Char, startIndex As Integer, count As Integer) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: Char

Carattere da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

count: Int32

Numero di elementi nella sezione in cui eseguire la ricerca.

Restituisce

Int32

Eccezioni

ArgumentNullException

source è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

-oppure-

count è minore di zero.

-oppure-

startIndex e count non specificano una sezione valida in source.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una parte di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 8;
   
   // iL is the length of the substring.
   int iL = 18;
   
   // myT1 and myT2 are the strings used for padding.
   String^ myT1 = gcnew String( '-',iS );
   String^ myT2;
   
   // Searches for the ligature Ã†.
   String^ myStr = "Is AE or ae the same as Ã† or Ã¦?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã† : ", myComp->IndexOf( myStr, L'Ã†', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã†', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¦ : ", myComp->IndexOf( myStr, L'Ã¦', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¦', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   myT2 = gcnew String( '-',myStr->Length - iS - iL );
   Console::WriteLine();
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL ) );
   Console::WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr->Substring( iS, iL ), myT2 );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ãœ : ", myComp->IndexOf( myStr, L'Ãœ', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ãœ', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ã¼ : ", myComp->IndexOf( myStr, L'Ã¼', iS, iL, CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ã¼', iS + iL - 1, iL, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

Original      : Is AE or ae the same as Ã† or Ã¦?
No options    : -------- ae the same as Ã† -----
           AE :                         b
           ae :          b
            Ã† :                         b
            Ã¦ :          b
Ordinal       : -------- ae the same as Ã† -----
           AE :
           ae :          b
            Ã† :                         b
            Ã¦ :
IgnoreCase    : -------- ae the same as Ã† -----
           AE :          f              l
           ae :          f              l
            Ã† :          f              l
            Ã¦ :          f              l

Original      : Is U" or u" the same as Ãœ or Ã¼?
No options    : -------- u" the same as Ãœ -----
           U" :                         b
           u" :          b
            Ãœ :                         b
            Ã¼ :          b
Ordinal       : -------- u" the same as Ãœ -----
           U" :
           u" :          b
            Ãœ :                         b
            Ã¼ :
IgnoreCase    : -------- u" the same as Ãœ -----
           U" :          f              l
           u" :          f              l
            Ãœ :          f              l
            Ã¼ :          f              l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 8;
      // iL is the length of the substring.
      int iL = 18;
      // myT1 and myT2 are the strings used for padding.
      String myT1 = new String( '-', iS );
      String myT2;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      myT2 = new String( '-', myStr.Length - iS - iL );
      Console.WriteLine();
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL ) );
      Console.WriteLine( "Ordinal       : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring( iS, iL ), myT2 );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, iL, CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', iS + iL - 1, iL, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

Original      : Is AE or ae the same as Æ or æ?
No options    : -------- ae the same as Æ -----
           AE :                         b
           ae :          b
            Æ :                         b
            æ :          b
Ordinal       : -------- ae the same as Æ -----
           AE :
           ae :          b
            Æ :                         b
            æ :
IgnoreCase    : -------- ae the same as Æ -----
           AE :          f              l
           ae :          f              l
            Æ :          f              l
            æ :          f              l

Original      : Is U" or u" the same as Ü or ü?
No options    : -------- u" the same as Ü -----
           U" :                         b
           u" :          b
            Ü :                         b
            ü :          b
Ordinal       : -------- u" the same as Ü -----
           U" :
           u" :          b
            Ü :                         b
            ü :
IgnoreCase    : -------- u" the same as Ü -----
           U" :          f              l
           u" :          f              l
            Ü :          f              l
            ü :          f              l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 8
      ' iL is the length of the substring.
      Dim iL As Integer = 18
      ' myT1 and myT2 are the strings used for padding.
      Dim myT1 As New [String]("-"c, [iS])
      Dim myT2 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      myT2 = New [String]("-"c, myStr.Length - [iS] - iL)
      Console.WriteLine()
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL))
      Console.WriteLine("Ordinal       : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}{2}", myT1, myStr.Substring([iS], iL), myT2)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], iL, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, [iS] + iL - 1, iL, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------- ae the same as Æ -----
'           AE :                         b
'           ae :          b
'            Æ :                         b
'            æ :          b
'Ordinal       : -------- ae the same as Æ -----
'           AE :
'           ae :          b
'            Æ :                         b
'            æ :
'IgnoreCase    : -------- ae the same as Æ -----
'           AE :          f              l
'           ae :          f              l
'            Æ :          f              l
'            æ :          f              l
'
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------- u" the same as Ü -----
'           U" :                         b
'           u" :          b
'            Ü :                         b
'            ü :          b
'Ordinal       : -------- u" the same as Ü -----
'           U" :
'           u" :          b
'            Ü :                         b
'            ü :
'IgnoreCase    : -------- u" the same as Ü -----
'           U" :          f              l
'           u" :          f              l
'            Ü :          f              l
'            ü :          f              l

Commenti

La stringa di origine viene eseguita una ricerca indietro a startIndex partire da e termina a startIndex - count + 1.

Questo overload esegue una ricerca sensibile alle impostazioni cultura. Se il carattere è un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), potrebbe essere considerata equivalente a qualsiasi occorrenza dei relativi componenti nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Per eseguire una ricerca ordinale (insensibile) in cui un carattere viene considerato equivalente a un altro carattere solo se i valori Unicode sono uguali, è necessario chiamare uno degli overload con un parametro di tipo CompareOptions e usare il Ordinal valore. Gli overload di String.LastIndexOf tale ricerca di un carattere eseguono una ricerca ordinale, mentre quelli che cercano una stringa eseguono una ricerca sensibile alle impostazioni cultura.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che non vengono considerati quando si esegue un ordinamento linguistico o con distinzione tra impostazioni cultura. In una ricerca sensibile alle impostazioni cultura, se value è un carattere ignorabile, il risultato equivale alla ricerca con tale carattere rimosso. In questo caso, il LastIndexOf(String, Char, Int32, Int32) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca. Nell'esempio seguente viene usato il LastIndexOf(String, Char, Int32, Int32) metodo per trovare un trattino morbido (U+00AD) che precede l'ultimo "m" in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In entrambi i casi, poiché il trattino morbido è un carattere ignorabile, il metodo restituisce la posizione di indice di "m", ovvero il valore di startIndex.

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable8.cs" id="Snippet9"::: code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable8.vb" id="Snippet9":::

Vedi anche

IndexOf(String, Char)

Si applica a

LastIndexOf(String, Char, Int32, CompareOptions)

Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato, usando il valore CompareOptions specificato.

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex, System::Globalization::CompareOptions options);

public:
 int LastIndexOf(System::String ^ source, char value, int startIndex, System::Globalization::CompareOptions options);

public virtual int LastIndexOf (string source, char value, int startIndex, System.Globalization.CompareOptions options);

public int LastIndexOf (string source, char value, int startIndex, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * char * int * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * char * int * System.Globalization.CompareOptions -> int

member this.LastIndexOf : string * char * int * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer, options As CompareOptions) As Integer

Public Function LastIndexOf (source As String, value As Char, startIndex As Integer, options As CompareOptions) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: Char

Carattere da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

options: CompareOptions

Restituisce

Int32

Eccezioni

ArgumentNullException

source è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

ArgumentException

options contiene un valore di CompareOptions non valido.

Esempio

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 20;
   
   // myT1 is the string used for padding.
   String^ myT1;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Commenti

La stringa di origine viene eseguita una ricerca indietro a startIndex partire da e termina all'inizio della stringa.

Il CompareOptions.StringSort valore non è valido per questo metodo.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che non vengono considerati quando si esegue un ordinamento linguistico o con distinzione tra impostazioni cultura. In una ricerca sensibile alle impostazioni cultura, se value è un carattere ignorabile, il risultato equivale alla ricerca con tale carattere rimosso. In questo caso, il LastIndexOf(String, Char, Int32, CompareOptions) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca. Nell'esempio seguente viene usato il LastIndexOf(String, Char, Int32, CompareOptions) metodo per trovare un trattino morbido (U+00AD) che precede l'ultimo "m" in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In entrambi i casi, poiché il trattino morbido è un carattere ignorabile, una ricerca sensibile alle impostazioni cultura restituisce la posizione dell'indice di "m". Una ricerca ordinale, tuttavia, trova correttamente il trattino morbido in una stringa e segnala che è assente dalla seconda stringa.

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable7.cs" id="Snippet8"::: code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable7.vb" id="Snippet8":::

Vedi anche

Si applica a

LastIndexOf(ReadOnlySpan<Char>, ReadOnlySpan<Char>, CompareOptions, Int32)

Cerca l'ultima occorrenza di una sottostringa all'interno di una stringa di origine.

public:
 int LastIndexOf(ReadOnlySpan<char> source, ReadOnlySpan<char> value, System::Globalization::CompareOptions options, [Runtime::InteropServices::Out] int % matchLength);

public int LastIndexOf (ReadOnlySpan<char> source, ReadOnlySpan<char> value, System.Globalization.CompareOptions options, out int matchLength);

member this.LastIndexOf : ReadOnlySpan<char> * ReadOnlySpan<char> * System.Globalization.CompareOptions * int -> int

Public Function LastIndexOf (source As ReadOnlySpan(Of Char), value As ReadOnlySpan(Of Char), options As CompareOptions, ByRef matchLength As Integer) As Integer

Parametri

source: ReadOnlySpan<Char>

Intervallo di caratteri di sola lettura in cui eseguire la ricerca.

value: ReadOnlySpan<Char>

Intervallo di caratteri di sola lettura contenente la sottostringa da individuare in source.

options: CompareOptions

Proprietà CompareOptions da utilizzare durante la ricerca.

matchLength: Int32

Quando termina, questo metodo contiene il numero di caratteri di source che corrispondono al valore desiderato. Questo valore può essere diverso dalla lunghezza di value se viene eseguito un confronto linguistico. Impostare su 0 se value non si trova in source.

Restituisce

Int32

Indice in base zero in source in cui la sottostringa value compare per l'ultima volta oppure un numero negativo se non è possibile trovare value all'interno di source.

Eccezioni

ArgumentException

options contiene una combinazione non supportata di flag.

Commenti

Questo metodo ha un sovraccarico maggiore di altri LastIndexOf overload che non accettano un matchLength argomento. Chiamare questo overload solo se sono necessarie le informazioni sulla lunghezza della corrispondenza.

Si applica a

LastIndexOf(String, Char)

Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine.

public:
 virtual int LastIndexOf(System::String ^ source, char value);

public:
 int LastIndexOf(System::String ^ source, char value);

public virtual int LastIndexOf (string source, char value);

public int LastIndexOf (string source, char value);

abstract member LastIndexOf : string * char -> int
override this.LastIndexOf : string * char -> int

member this.LastIndexOf : string * char -> int

Public Overridable Function LastIndexOf (source As String, value As Char) As Integer

Public Function LastIndexOf (source As String, value As Char) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: Char

Carattere da individuare all'interno di source.

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value all'interno di source, se presente; in caso contrario, -1.

Eccezioni

ArgumentNullException

source è null.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE" ), myComp->LastIndexOf( myStr, "AE" ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae" ), myComp->LastIndexOf( myStr, "ae" ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ' ), myComp->LastIndexOf( myStr, L'Æ' ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ' ), myComp->LastIndexOf( myStr, L'æ' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308" ), myComp->LastIndexOf( myStr, "U\u0308" ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308" ), myComp->LastIndexOf( myStr, "u\u0308" ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü' ), myComp->LastIndexOf( myStr, L'Ü' ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü' ), myComp->LastIndexOf( myStr, L'ü' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Commenti

La stringa di origine viene eseguita una ricerca indietro a partire dalla fine della stringa e termina all'inizio della stringa.

Questo overload esegue una ricerca sensibile alle impostazioni cultura. Se il carattere è un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), potrebbe essere considerata equivalente a qualsiasi occorrenza dei relativi componenti nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Per eseguire una ricerca ordinale (senza distinzione tra impostazioni cultura), in cui un carattere viene considerato equivalente a un altro carattere solo se i valori Unicode sono uguali, è necessario chiamare uno degli overload con un parametro di tipo CompareOptions e usare il Ordinal valore . Gli overload di String.LastIndexOf tale ricerca di un carattere eseguono una ricerca ordinale, mentre quelli che cercano una stringa eseguono una ricerca sensibile alle impostazioni cultura.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che sono caratteri non considerati durante l'esecuzione di un ordinamento linguistico o sensibile alle impostazioni cultura. In una ricerca sensibile alle impostazioni cultura, se value è un carattere ignorabile, il risultato equivale alla ricerca con tale carattere rimosso. In questo caso, il LastIndexOf(String, Char) metodo restituisce sempre l'ultima posizione di indice in source per indicare che la corrispondenza viene trovata alla fine di source. Nell'esempio seguente il LastIndexOf(String, Char) metodo viene usato per trovare il trattino morbido (U+00AD) in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In entrambi i casi, poiché il trattino morbido è un carattere ignorabile, il metodo restituisce l'ultima posizione di indice nella stringa per indicare che ha trovato una corrispondenza alla fine della stringa.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the index of the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, '\u00AD'));
      Console.WriteLine(ci.LastIndexOf(s2, '\u00AD'));
   }
}
// The example displays the following output:
//       6
//       5

Vedi anche

IndexOf(String, Char)

Si applica a

LastIndexOf(String, String, CompareOptions)

Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine usando il valore CompareOptions specificato.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, System::Globalization::CompareOptions options);

public:
 int LastIndexOf(System::String ^ source, System::String ^ value, System::Globalization::CompareOptions options);

public virtual int LastIndexOf (string source, string value, System.Globalization.CompareOptions options);

public int LastIndexOf (string source, string value, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * string * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * string * System.Globalization.CompareOptions -> int

member this.LastIndexOf : string * string * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As String, options As CompareOptions) As Integer

Public Function LastIndexOf (source As String, value As String, options As CompareOptions) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: String

Stringa da individuare all'interno di source.

options: CompareOptions

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value se presente, all'interno di source usando le opzioni di confronto specificate; in caso contrario, -1.

Eccezioni

ArgumentNullException

source è null.

-oppure-

value è null.

ArgumentException

options contiene un valore di CompareOptions non valido.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE" ), myComp->LastIndexOf( myStr, "AE" ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae" ), myComp->LastIndexOf( myStr, "ae" ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ' ), myComp->LastIndexOf( myStr, L'Æ' ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ' ), myComp->LastIndexOf( myStr, L'æ' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308" ), myComp->LastIndexOf( myStr, "U\u0308" ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308" ), myComp->LastIndexOf( myStr, "u\u0308" ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü' ), myComp->LastIndexOf( myStr, L'Ü' ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü' ), myComp->LastIndexOf( myStr, L'ü' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Commenti

La stringa di origine viene eseguita una ricerca indietro a partire dalla fine della stringa e termina all'inizio della stringa.

Il CompareOptions.StringSort valore non è valido per questo metodo.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che non vengono considerati quando si esegue un ordinamento linguistico o con distinzione tra impostazioni cultura. In una ricerca dipendente dalle impostazioni cultura (ovvero se options non è Ordinal o OrdinalIgnoreCase), se value contiene un carattere ignorable, il risultato è equivalente alla ricerca con il carattere rimosso. Se value è costituito solo da uno o più caratteri ignorabili, il LastIndexOf(String, String, CompareOptions) metodo restituisce sourcesempre .Length - 1, che rappresenta l'ultima posizione dell'indice in source. Nell'esempio seguente viene usato il LastIndexOf(String, String, CompareOptions) metodo per trovare tre sottostringa (un trattino morbido (U+00AD), un trattino morbido seguito da "n" e un trattino morbido seguito da "m") in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. Poiché il trattino morbido è un carattere ignorabile, una ricerca sensibile alle impostazioni cultura restituisce lo stesso valore restituito se il trattino morbido non era incluso nella stringa di ricerca. Una ricerca ordinale, tuttavia, trova correttamente il trattino morbido in una stringa e segnala che è assente dalla seconda stringa.

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable5.cs" id="Snippet6"::: code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable5.vb" id="Snippet6":::

Vedi anche

Si applica a

LastIndexOf(String, Char, Int32)

public:
 int LastIndexOf(System::String ^ source, char value, int startIndex);

public:
 virtual int LastIndexOf(System::String ^ source, char value, int startIndex);

public int LastIndexOf (string source, char value, int startIndex);

public virtual int LastIndexOf (string source, char value, int startIndex);

member this.LastIndexOf : string * char * int -> int

abstract member LastIndexOf : string * char * int -> int
override this.LastIndexOf : string * char * int -> int

Public Function LastIndexOf (source As String, value As Char, startIndex As Integer) As Integer

Public Overridable Function LastIndexOf (source As String, value As Char, startIndex As Integer) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: Char

Carattere da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value, se presente, all'interno della sezione di source compresa tra l'inizio di source e startIndex; in caso contrario, -1. Restituisce startIndex se value è un carattere che è possibile ignorare.

Eccezioni

ArgumentNullException

source è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una parte di una stringa. Si noti che IndexOf e LastIndexOf vengono eseguite ricerche in parti diverse della stringa, anche con lo stesso startIndex parametro.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 20;
   
   // myT1 is the string used for padding.
   String^ myT1;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Commenti

La stringa di origine viene eseguita una ricerca all'indietro a partire da startIndex e termina all'inizio della stringa.

Questo overload esegue una ricerca sensibile alle impostazioni cultura. Se il carattere è un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), può essere considerata equivalente a qualsiasi occorrenza dei relativi componenti nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Per eseguire una ricerca ordinale (senza distinzione tra impostazioni cultura), in cui un carattere viene considerato equivalente a un altro carattere solo se i valori Unicode sono uguali, è necessario chiamare uno degli overload con un parametro di tipo CompareOptions e usare il Ordinal valore . Gli overload di String.LastIndexOf tale ricerca di un carattere eseguono una ricerca ordinale, mentre quelli che cercano una stringa eseguono una ricerca sensibile alle impostazioni cultura.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che sono caratteri non considerati durante l'esecuzione di un ordinamento linguistico o sensibile alle impostazioni cultura. In una ricerca sensibile alle impostazioni cultura, se value è un carattere ignorabile, il risultato equivale alla ricerca con tale carattere rimosso. In questo caso, il LastIndexOf(String, Char, Int32) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca. Nell'esempio seguente il LastIndexOf(String, Char, Int32) metodo viene usato per trovare un trattino morbido (U+00AD) che precede l'ultimo "m" in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In entrambi i casi, poiché il trattino morbido è un carattere ignorabile, il metodo restituisce la posizione di indice di "m", ovvero il valore di startIndex.

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable4.cs" id="Snippet5":: ::code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable4.vb" id="Snippet5":

Vedi anche

IndexOf(String, Char)

Si applica a

LastIndexOf(String, Char, CompareOptions)

Cerca il carattere specificato e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine usando il valore CompareOptions specificato.

public:
 virtual int LastIndexOf(System::String ^ source, char value, System::Globalization::CompareOptions options);

public:
 int LastIndexOf(System::String ^ source, char value, System::Globalization::CompareOptions options);

public virtual int LastIndexOf (string source, char value, System.Globalization.CompareOptions options);

public int LastIndexOf (string source, char value, System.Globalization.CompareOptions options);

abstract member LastIndexOf : string * char * System.Globalization.CompareOptions -> int
override this.LastIndexOf : string * char * System.Globalization.CompareOptions -> int

member this.LastIndexOf : string * char * System.Globalization.CompareOptions -> int

Public Overridable Function LastIndexOf (source As String, value As Char, options As CompareOptions) As Integer

Public Function LastIndexOf (source As String, value As Char, options As CompareOptions) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: Char

Carattere da individuare all'interno di source.

options: CompareOptions

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value se presente, all'interno di source usando le opzioni di confronto specificate; in caso contrario, -1.

Eccezioni

ArgumentNullException

source è null.

ArgumentException

options contiene un valore di CompareOptions non valido.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE" ), myComp->LastIndexOf( myStr, "AE" ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae" ), myComp->LastIndexOf( myStr, "ae" ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ' ), myComp->LastIndexOf( myStr, L'Æ' ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ' ), myComp->LastIndexOf( myStr, L'æ' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308" ), myComp->LastIndexOf( myStr, "U\u0308" ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308" ), myComp->LastIndexOf( myStr, "u\u0308" ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü' ), myComp->LastIndexOf( myStr, L'Ü' ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü' ), myComp->LastIndexOf( myStr, L'ü' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Commenti

La stringa di origine viene eseguita una ricerca all'indietro a partire dalla fine della stringa e termina all'inizio della stringa.

Il CompareOptions.StringSort valore non è valido per questo metodo.

Se options non include il Ordinal valore, questo overload esegue una ricerca sensibile alle impostazioni cultura. Se il carattere è un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), può essere considerata equivalente a qualsiasi occorrenza dei relativi componenti nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Se options include il Ordinal valore, questo overload esegue una ricerca ordinale (senza distinzione tra impostazioni cultura). Un carattere viene considerato equivalente a un altro carattere solo se i valori Unicode sono uguali. Gli overload di String.LastIndexOf tale ricerca di un carattere eseguono una ricerca ordinale, mentre quelli che cercano una stringa eseguono una ricerca sensibile alle impostazioni cultura.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che sono caratteri non considerati durante l'esecuzione di un ordinamento linguistico o sensibile alle impostazioni cultura. In una ricerca sensibile alle impostazioni cultura, se value è un carattere ignorabile, il risultato equivale alla ricerca con tale carattere rimosso. In questo caso, il LastIndexOf(String, Char, CompareOptions) metodo restituisce sempre l'ultima posizione del carattere in source per indicare che la corrispondenza viene trovata alla fine di source. Nell'esempio seguente il LastIndexOf(String, Char, CompareOptions) metodo viene usato per cercare un trattino morbido (U+00AD) in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In entrambi i casi, poiché il trattino morbido è un carattere ignorabile, una ricerca con distinzione delle impostazioni cultura restituisce l'ultima posizione dell'indice nella stringa di origine. Al contrario, una ricerca ordinale trova correttamente il trattino morbido in una stringa e segnala che è assente dalla seconda stringa.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the last index of the soft hyphen using culture-sensitive comparison.
      Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', CompareOptions.IgnoreCase));
      Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', CompareOptions.IgnoreCase));

      // Find the last index of the soft hyphen using ordinal comparison.
      Console.WriteLine(ci.LastIndexOf(s1, '\u00AD', CompareOptions.Ordinal));
      Console.WriteLine(ci.LastIndexOf(s2, '\u00AD', CompareOptions.Ordinal));
   }
}
// The example displays the following output:
//       6
//       5
//       3
//       -1

Vedi anche

Si applica a

LastIndexOf(ReadOnlySpan<Char>, Rune, CompareOptions)

Cerca l'ultima occorrenza di un oggetto Rune all'interno dell'intervallo di caratteri di sola lettura specificato.

public int LastIndexOf (ReadOnlySpan<char> source, System.Text.Rune value, System.Globalization.CompareOptions options = System.Globalization.CompareOptions.None);

member this.LastIndexOf : ReadOnlySpan<char> * System.Text.Rune * System.Globalization.CompareOptions -> int

Public Function LastIndexOf (source As ReadOnlySpan(Of Char), value As Rune, Optional options As CompareOptions = System.Globalization.CompareOptions.None) As Integer

Parametri

source: ReadOnlySpan<Char>

Intervallo di caratteri di sola lettura in cui eseguire la ricerca.

value: Rune

Oggetto Rune da trovare in source.

options: CompareOptions

Combinazione facoltativa di valori di enumerazione di CompareOptions da usare durante la ricerca. Il valore predefinito è None.

Restituisce

Int32

Indice in base zero in source in cui value compare per l'ultima volta oppure un valore negativo se non è possibile trovare value all'interno di source.

Eccezioni

ArgumentException

options contiene una combinazione non supportata di flag.

Si applica a

LastIndexOf(ReadOnlySpan<Char>, ReadOnlySpan<Char>, CompareOptions)

Cerca l'ultima occorrenza di una sottostringa all'interno dell'intervallo di caratteri di sola lettura specificato.

public int LastIndexOf (ReadOnlySpan<char> source, ReadOnlySpan<char> value, System.Globalization.CompareOptions options = System.Globalization.CompareOptions.None);

member this.LastIndexOf : ReadOnlySpan<char> * ReadOnlySpan<char> * System.Globalization.CompareOptions -> int

Public Function LastIndexOf (source As ReadOnlySpan(Of Char), value As ReadOnlySpan(Of Char), Optional options As CompareOptions = System.Globalization.CompareOptions.None) As Integer

Parametri

source: ReadOnlySpan<Char>

Intervallo di caratteri di sola lettura in cui eseguire la ricerca.

value: ReadOnlySpan<Char>

Sottostringa da trovare in source.

options: CompareOptions

Combinazione facoltativa di valori di enumerazione di CompareOptions da usare durante la ricerca. Il valore predefinito è None.

Restituisce

Int32

Indice in base zero in source in cui la sottostringa value compare per l'ultima volta oppure un valore negativo se non è possibile trovare value all'interno di source.

Eccezioni

ArgumentException

options contiene una combinazione non supportata di flag.

Si applica a

LastIndexOf(String, String)

Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno dell'intera stringa di origine.

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value);

public:
 int LastIndexOf(System::String ^ source, System::String ^ value);

public virtual int LastIndexOf (string source, string value);

public int LastIndexOf (string source, string value);

abstract member LastIndexOf : string * string -> int
override this.LastIndexOf : string * string -> int

member this.LastIndexOf : string * string -> int

Public Overridable Function LastIndexOf (source As String, value As String) As Integer

Public Function LastIndexOf (source As String, value As String) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: String

Stringa da individuare all'interno di source.

Restituisce

Int32

Indice in base zero dell'ultima occorrenza di value all'interno di source, se presente; in caso contrario, -1.

Eccezioni

ArgumentNullException

source è null.

-oppure-

value è null.

Esempio

L'esempio seguente determina gli indici della prima e dell'ultima occorrenza di un carattere o di una sottostringa all'interno di una stringa.

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE" ), myComp->LastIndexOf( myStr, "AE" ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae" ), myComp->LastIndexOf( myStr, "ae" ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ' ), myComp->LastIndexOf( myStr, L'Æ' ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ' ), myComp->LastIndexOf( myStr, L'æ' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "AE", CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "ae", CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "AE", CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "ae", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Æ', CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'æ', CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   Console::WriteLine( "No options    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308" ), myComp->LastIndexOf( myStr, "U\u0308" ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308" ), myComp->LastIndexOf( myStr, "u\u0308" ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü' ), myComp->LastIndexOf( myStr, L'Ü' ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü' ), myComp->LastIndexOf( myStr, L'ü' ) );
   Console::WriteLine( "Ordinal       : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::Ordinal ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}", myStr );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "U\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, "u\u0308", CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'Ü', CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', CompareOptions::IgnoreCase ), myComp->LastIndexOf( myStr, L'ü', CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE" ), myComp.LastIndexOf( myStr, "AE" ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae" ), myComp.LastIndexOf( myStr, "ae" ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ' ), myComp.LastIndexOf( myStr, 'Æ' ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ' ), myComp.LastIndexOf( myStr, 'æ' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "AE", CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "ae", CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "AE", CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "ae", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Æ', CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'æ', CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();
      Console.WriteLine( "No options    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308" ), myComp.LastIndexOf( myStr, "U\u0308" ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308" ), myComp.LastIndexOf( myStr, "u\u0308" ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü' ), myComp.LastIndexOf( myStr, 'Ü' ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü' ), myComp.LastIndexOf( myStr, 'ü' ) );
      Console.WriteLine( "Ordinal       : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.Ordinal ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}", myStr );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "U\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, "u\u0308", CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'Ü', CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', CompareOptions.IgnoreCase ), myComp.LastIndexOf( myStr, 'ü', CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

No options    : Is AE or ae the same as Æ or æ?
           AE :    f                    l
           ae :          f                   l
            Æ :    f                    l
            æ :          f                   l
Ordinal       : Is AE or ae the same as Æ or æ?
           AE :    b
           ae :          b
            Æ :                         b
            æ :                              b
IgnoreCase    : Is AE or ae the same as Æ or æ?
           AE :    f                         l
           ae :    f                         l
            Æ :    f                         l
            æ :    f                         l

No options    : Is U" or u" the same as Ü or ü?
           U" :    f                    l
           u" :          f                   l
            Ü :    f                    l
            ü :          f                   l
Ordinal       : Is U" or u" the same as Ü or ü?
           U" :    b
           u" :          b
            Ü :                         b
            ü :                              b
IgnoreCase    : Is U" or u" the same as Ü or ü?
           U" :    f                         l
           u" :    f                         l
            Ü :    f                         l
            ü :    f                         l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE"), myComp.LastIndexOf(myStr, "AE"))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae"), myComp.LastIndexOf(myStr, "ae"))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c), myComp.LastIndexOf(myStr, "Æ"c))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c), myComp.LastIndexOf(myStr, "æ"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "AE", CompareOptions.Ordinal))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ae", CompareOptions.Ordinal))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.Ordinal))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "AE", CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ae", CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Æ"c, CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "æ"c, CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()
      Console.WriteLine("No options    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308)))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308)), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308)))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c), myComp.LastIndexOf(myStr, "Ü"c))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c), myComp.LastIndexOf(myStr, "ü"c))
      Console.WriteLine("Ordinal       : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.Ordinal))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.Ordinal))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.Ordinal), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}", myStr)
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "Ü"c, CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, CompareOptions.IgnoreCase), myComp.LastIndexOf(myStr, "ü"c, CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 
         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))

      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'No options    : Is AE or ae the same as Æ or æ?
'           AE :    f                    l
'           ae :          f                   l
'            Æ :    f                    l
'            æ :          f                   l
'Ordinal       : Is AE or ae the same as Æ or æ?
'           AE :    b
'           ae :          b
'            Æ :                         b
'            æ :                              b
'IgnoreCase    : Is AE or ae the same as Æ or æ?
'           AE :    f                         l
'           ae :    f                         l
'            Æ :    f                         l
'            æ :    f                         l
'
'No options    : Is U" or u" the same as Ü or ü?
'           U" :    f                    l
'           u" :          f                   l
'            Ü :    f                    l
'            ü :          f                   l
'Ordinal       : Is U" or u" the same as Ü or ü?
'           U" :    b
'           u" :          b
'            Ü :                         b
'            ü :                              b
'IgnoreCase    : Is U" or u" the same as Ü or ü?
'           U" :    f                         l
'           u" :    f                         l
'            Ü :    f                         l
'            ü :    f                         l

Commenti

La stringa di origine viene eseguita una ricerca all'indietro a partire dalla fine della stringa e termina all'inizio della stringa.

Questo overload esegue una ricerca sensibile alle impostazioni cultura. Un valore Unicode che rappresenta un carattere precomposto, ad esempio la legatura "Æ" (U+00C6), può essere considerato equivalente a qualsiasi occorrenza dei componenti del carattere nella sequenza corretta, ad esempio "AE" (U+0041, U+0045), a seconda delle impostazioni cultura. Per eseguire una ricerca ordinale (senza distinzione tra impostazioni cultura), in cui vengono confrontati i valori Unicode, è necessario chiamare uno degli overload con un parametro di tipo CompareOptions e usare il CompareOptions.Ordinal valore .

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che sono caratteri non considerati durante l'esecuzione di un ordinamento linguistico o sensibile alle impostazioni cultura. In una ricerca dipendente dalle impostazioni cultura, se value contiene un carattere ignorabile, il risultato è equivalente alla ricerca con il carattere rimosso. Se value è costituito solo da uno o più caratteri ignorabili, il LastIndexOf(String, String) metodo restituisce sourcesempre .Length - 1, che rappresenta l'ultima posizione dell'indice in source. Nell'esempio seguente il LastIndexOf(String, String) metodo viene usato per trovare tre sottostringhe (un trattino morbido (U+00AD), un trattino morbido seguito da "n" e un trattino morbido seguito da "m") in due stringhe. Solo una delle stringhe contiene un segno meno facoltativo. In ogni caso, poiché il trattino morbido è un carattere ignorabile, il risultato è lo stesso di se il trattino morbido non fosse stato incluso in value. Quando si cerca solo un trattino morbido, il metodo restituisce 6 e 5. Questi valori corrispondono all'indice dell'ultimo carattere nelle due stringhe.

using System;
using System.Globalization;

public class Example
{
   public static void Main()
   {
      CompareInfo ci = CultureInfo.CurrentCulture.CompareInfo;

      string s1 = "ani\u00ADmal";
      string s2 = "animal";

      // Find the index of the last soft hyphen.
      Console.WriteLine(ci.LastIndexOf(s1, "\u00AD"));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00AD"));

      // Find the index of the last soft hyphen followed by "n".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADn"));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADn"));

      // Find the index of the last soft hyphen followed by "m".
      Console.WriteLine(ci.LastIndexOf(s1, "\u00ADm"));
      Console.WriteLine(ci.LastIndexOf(s2, "\u00ADm"));
   }
}
// The example displays the following output:
//       6
//       5
//       1
//       1
//       4
//       3

Vedi anche

IndexOf(String, Char)

Si applica a

LastIndexOf(String, String, Int32)

Cerca la sottostringa specificata e restituisce l'indice in base zero dell'ultima occorrenza all'interno della sezione della stringa di origine compresa tra l'inizio della stringa e l'indice specificato.

public:
 int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex);

public:
 virtual int LastIndexOf(System::String ^ source, System::String ^ value, int startIndex);

public int LastIndexOf (string source, string value, int startIndex);

public virtual int LastIndexOf (string source, string value, int startIndex);

member this.LastIndexOf : string * string * int -> int

abstract member LastIndexOf : string * string * int -> int
override this.LastIndexOf : string * string * int -> int

Public Function LastIndexOf (source As String, value As String, startIndex As Integer) As Integer

Public Overridable Function LastIndexOf (source As String, value As String, startIndex As Integer) As Integer

Parametri

source: String

Stringa in cui effettuare la ricerca.

value: String

Stringa da individuare all'interno di source.

startIndex: Int32

Indice iniziale in base zero della ricerca all'indietro.

Restituisce

Int32

Eccezioni

ArgumentNullException

source è null.

-oppure-

value è null.

ArgumentOutOfRangeException

startIndex non è compreso nell'intervallo di indici validi per source.

Esempio

using namespace System;
using namespace System::Globalization;
void PrintMarker( String^ Prefix, int First, int Last )
{
   
   // Determines the size of the array to create.
   int mySize;
   if ( Last > First )
      mySize = Last;
   else
      mySize = First;

   if ( mySize > -1 )
   {
      
      // Creates an array of Char to hold the markers.
      array<Char>^myCharArr = gcnew array<Char>(mySize + 1);
      
      // Inserts the appropriate markers.
      if ( First > -1 )
            myCharArr[ First ] = 'f';
      if ( Last > -1 )
            myCharArr[ Last ] = 'l';
      if ( First == Last )
            myCharArr[ First ] = 'b';
      
      // Displays the array of Char as a String.
      Console::WriteLine( "{0}{1}", Prefix, gcnew String( myCharArr ) );
   }
   else
      Console::WriteLine( Prefix );
}

int main()
{
   
   // Creates CompareInfo for the InvariantCulture.
   CompareInfo^ myComp = CultureInfo::InvariantCulture->CompareInfo;
   
   // iS is the starting index of the substring.
   int iS = 20;
   
   // myT1 is the string used for padding.
   String^ myT1;
   
   // Searches for the ligature Æ.
   String^ myStr = "Is AE or ae the same as Æ or æ?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           AE : ", myComp->IndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           ae : ", myComp->IndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Æ : ", myComp->IndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            æ : ", myComp->IndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           AE : ", -1, myComp->LastIndexOf( myStr, "AE", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           ae : ", -1, myComp->LastIndexOf( myStr, "ae", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Æ : ", -1, myComp->LastIndexOf( myStr, L'Æ', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            æ : ", -1, myComp->LastIndexOf( myStr, L'æ', iS, CompareOptions::IgnoreCase ) );
   
   // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
   myStr = "Is U\u0308 or u\u0308 the same as \u00DC or \u00FC?";
   Console::WriteLine();
   myT1 = gcnew String( '-',iS );
   Console::WriteLine( "IndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS ), -1 );
   Console::WriteLine( "Ordinal       : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ), -1 );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr->Substring( iS ) );
   PrintMarker( "           U\u0308 : ", myComp->IndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "           u\u0308 : ", myComp->IndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            Ü : ", myComp->IndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ), -1 );
   PrintMarker( "            ü : ", myComp->IndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ), -1 );
   myT1 = gcnew String( '-',myStr->Length - iS - 1 );
   Console::WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
   Console::WriteLine( "Original      : {0}", myStr );
   Console::WriteLine( "No options    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS ) );
   Console::WriteLine( "Ordinal       : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::Ordinal ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::Ordinal ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::Ordinal ) );
   Console::WriteLine( "IgnoreCase    : {0}{1}", myStr->Substring( 0, iS + 1 ), myT1 );
   PrintMarker( "           U\u0308 : ", -1, myComp->LastIndexOf( myStr, "U\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "           u\u0308 : ", -1, myComp->LastIndexOf( myStr, "u\u0308", iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            Ü : ", -1, myComp->LastIndexOf( myStr, L'Ü', iS, CompareOptions::IgnoreCase ) );
   PrintMarker( "            ü : ", -1, myComp->LastIndexOf( myStr, L'ü', iS, CompareOptions::IgnoreCase ) );
}

/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

using System;
using System.Globalization;

public class SamplesCompareInfo  {

   public static void Main()  {

      // Creates CompareInfo for the InvariantCulture.
      CompareInfo myComp = CultureInfo.InvariantCulture.CompareInfo;

      // iS is the starting index of the substring.
      int iS = 20;
      // myT1 is the string used for padding.
      String myT1;

      // Searches for the ligature Æ.
      String myStr = "Is AE or ae the same as Æ or æ?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           AE : ", myComp.IndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           ae : ", myComp.IndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Æ : ", myComp.IndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            æ : ", myComp.IndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           AE : ", -1, myComp.LastIndexOf( myStr, "AE", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           ae : ", -1, myComp.LastIndexOf( myStr, "ae", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Æ : ", -1, myComp.LastIndexOf( myStr, 'Æ', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            æ : ", -1, myComp.LastIndexOf( myStr, 'æ', iS, CompareOptions.IgnoreCase ) );

      // Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is \u0055\u0308 or \u0075\u0308 the same as \u00DC or \u00FC?";
      Console.WriteLine();

      myT1 = new String( '-', iS );
      Console.WriteLine( "IndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS ), -1 );
      Console.WriteLine( "Ordinal       : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ), -1 );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myT1, myStr.Substring( iS ) );
      PrintMarker( "           U\u0308 : ", myComp.IndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "           u\u0308 : ", myComp.IndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            Ü : ", myComp.IndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ), -1 );
      PrintMarker( "            ü : ", myComp.IndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ), -1 );

      myT1 = new String( '-', myStr.Length - iS - 1 );
      Console.WriteLine( "LastIndexOf( String, *, {0}, * )", iS );
      Console.WriteLine( "Original      : {0}", myStr );
      Console.WriteLine( "No options    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS ) );
      Console.WriteLine( "Ordinal       : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.Ordinal ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.Ordinal ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.Ordinal ) );
      Console.WriteLine( "IgnoreCase    : {0}{1}", myStr.Substring( 0, iS + 1 ), myT1 );
      PrintMarker( "           U\u0308 : ", -1, myComp.LastIndexOf( myStr, "U\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "           u\u0308 : ", -1, myComp.LastIndexOf( myStr, "u\u0308", iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            Ü : ", -1, myComp.LastIndexOf( myStr, 'Ü', iS, CompareOptions.IgnoreCase ) );
      PrintMarker( "            ü : ", -1, myComp.LastIndexOf( myStr, 'ü', iS, CompareOptions.IgnoreCase ) );
   }

   public static void PrintMarker( String Prefix, int First, int Last )  {

      // Determines the size of the array to create.
      int mySize;
      if ( Last > First )
         mySize = Last;
      else
         mySize = First;

      if ( mySize > -1 )  {

         // Creates an array of Char to hold the markers.
         Char[] myCharArr = new Char[mySize+1];

         // Inserts the appropriate markers.
         if ( First > -1 )
         myCharArr[First] = 'f';
         if ( Last > -1 )
            myCharArr[Last] = 'l';
         if ( First == Last )
         myCharArr[First] = 'b';

         // Displays the array of Char as a String.
         Console.WriteLine( "{0}{1}", Prefix, new String( myCharArr ) );
      }
      else
        {
            Console.WriteLine( Prefix );
        }
    }
}


/*
This code produces the following output.

IndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : -------------------- as Æ or æ?
           AE :                         f
           ae :                              f
            Æ :                         f
            æ :                              f
Ordinal       : -------------------- as Æ or æ?
           AE :
           ae :
            Æ :                         f
            æ :                              f
IgnoreCase    : -------------------- as Æ or æ?
           AE :                         f
           ae :                         f
            Æ :                         f
            æ :                         f
LastIndexOf( String, *, 20, * )
Original      : Is AE or ae the same as Æ or æ?
No options    : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :    l
            æ :          l
Ordinal       : Is AE or ae the same ----------
           AE :    l
           ae :          l
            Æ :
            æ :
IgnoreCase    : Is AE or ae the same ----------
           AE :          l
           ae :          l
            Æ :          l
            æ :          l

IndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : -------------------- as Ü or ü?
           U" :                         f
           u" :                              f
            Ü :                         f
            ü :                              f
Ordinal       : -------------------- as Ü or ü?
           U" :
           u" :
            Ü :                         f
            ü :                              f
IgnoreCase    : -------------------- as Ü or ü?
           U" :                         f
           u" :                         f
            Ü :                         f
            ü :                         f
LastIndexOf( String, *, 20, * )
Original      : Is U" or u" the same as Ü or ü?
No options    : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :    l
            ü :          l
Ordinal       : Is U" or u" the same ----------
           U" :    l
           u" :          l
            Ü :
            ü :
IgnoreCase    : Is U" or u" the same ----------
           U" :          l
           u" :          l
            Ü :          l
            ü :          l

*/

Imports System.Globalization

Public Class SamplesCompareInfo

   Public Shared Sub Main()

      ' Creates CompareInfo for the InvariantCulture.
      Dim myComp As CompareInfo = CultureInfo.InvariantCulture.CompareInfo

      ' iS is the starting index of the substring.
      Dim [iS] As Integer = 20
      ' myT1 is the string used for padding.
      Dim myT1 As [String]

      ' Searches for the ligature Æ.
      Dim myStr As [String] = "Is AE or ae the same as Æ or æ?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS]), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS]), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS]), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           AE : ", myComp.IndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           ae : ", myComp.IndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Æ : ", myComp.IndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            æ : ", myComp.IndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS]))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS]))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS]))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.Ordinal))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.Ordinal))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           AE : ", - 1, myComp.LastIndexOf(myStr, "AE", [iS], CompareOptions.IgnoreCase))
      PrintMarker("           ae : ", - 1, myComp.LastIndexOf(myStr, "ae", [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Æ : ", - 1, myComp.LastIndexOf(myStr, "Æ"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            æ : ", - 1, myComp.LastIndexOf(myStr, "æ"c, [iS], CompareOptions.IgnoreCase))

      ' Searches for the combining character sequence Latin capital letter U with diaeresis or Latin small letter u with diaeresis.
      myStr = "Is " & ChrW(&H0055) & ChrW(&H0308) & " or " & ChrW(&H0075) & ChrW(&H0308) & " the same as " & ChrW(&H00DC) & " or " & ChrW(&H00FC) & "?"
      Console.WriteLine()

      myT1 = New [String]("-"c, [iS])
      Console.WriteLine("IndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS]), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS]), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS]), - 1)
      Console.WriteLine("Ordinal       : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal), - 1)
      Console.WriteLine("IgnoreCase    : {0}{1}", myT1, myStr.Substring([iS]))
      PrintMarker("           U" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("           u" & ChrW(&H0308) & " : ", myComp.IndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            Ü : ", myComp.IndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase), - 1)
      PrintMarker("            ü : ", myComp.IndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase), - 1)

      myT1 = New [String]("-"c, myStr.Length - [iS] - 1)
      Console.WriteLine("LastIndexOf( String, *, {0}, * )", [iS])
      Console.WriteLine("Original      : {0}", myStr)
      Console.WriteLine("No options    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS]))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS]))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS]))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS]))
      Console.WriteLine("Ordinal       : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.Ordinal))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.Ordinal))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.Ordinal))
      Console.WriteLine("IgnoreCase    : {0}{1}", myStr.Substring(0, [iS] + 1), myT1)
      PrintMarker("           U" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "U" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("           u" & ChrW(&H0308) & " : ", - 1, myComp.LastIndexOf(myStr, "u" & ChrW(&H0308), [iS], CompareOptions.IgnoreCase))
      PrintMarker("            Ü : ", - 1, myComp.LastIndexOf(myStr, "Ü"c, [iS], CompareOptions.IgnoreCase))
      PrintMarker("            ü : ", - 1, myComp.LastIndexOf(myStr, "ü"c, [iS], CompareOptions.IgnoreCase))

   End Sub

   Public Shared Sub PrintMarker(Prefix As [String], First As Integer, Last As Integer)

      ' Determines the size of the array to create.
      Dim mySize As Integer
      If Last > First Then
         mySize = Last
      Else
         mySize = First
      End If 

      If mySize > - 1 Then

         ' Creates an array of Char to hold the markers.
         Dim myCharArr(mySize + 1) As [Char]

         ' Inserts the appropriate markers.
         If First > - 1 Then
            myCharArr(First) = "f"c
         End If
         If Last > - 1 Then
            myCharArr(Last) = "l"c
         End If
         If First = Last Then
            myCharArr(First) = "b"c
         End If 

         ' Displays the array of Char as a String.
         Console.WriteLine("{0}{1}", Prefix, New [String](myCharArr))
      
      Else
         Console.WriteLine(Prefix)

      End If 

   End Sub

End Class


'This code produces the following output.
'
'IndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                              f
'            Æ :                         f
'            æ :                              f
'Ordinal       : -------------------- as Æ or æ?
'           AE :
'           ae :
'            Æ :                         f
'            æ :                              f
'IgnoreCase    : -------------------- as Æ or æ?
'           AE :                         f
'           ae :                         f
'            Æ :                         f
'            æ :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is AE or ae the same as Æ or æ?
'No options    : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :    l
'            æ :          l
'Ordinal       : Is AE or ae the same ----------
'           AE :    l
'           ae :          l
'            Æ :
'            æ :
'IgnoreCase    : Is AE or ae the same ----------
'           AE :          l
'           ae :          l
'            Æ :          l
'            æ :          l
'
'IndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                              f
'            Ü :                         f
'            ü :                              f
'Ordinal       : -------------------- as Ü or ü?
'           U" :
'           u" :
'            Ü :                         f
'            ü :                              f
'IgnoreCase    : -------------------- as Ü or ü?
'           U" :                         f
'           u" :                         f
'            Ü :                         f
'            ü :                         f
'LastIndexOf( String, *, 20, * )
'Original      : Is U" or u" the same as Ü or ü?
'No options    : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :    l
'            ü :          l
'Ordinal       : Is U" or u" the same ----------
'           U" :    l
'           u" :          l
'            Ü :
'            ü :
'IgnoreCase    : Is U" or u" the same ----------
'           U" :          l
'           u" :          l
'            Ü :          l
'            ü :          l

Commenti

La stringa di origine viene eseguita una ricerca indietro a startIndex partire da e termina all'inizio della stringa.

Nota

Note per i chiamanti

I set di caratteri includono caratteri ignorabili, che non vengono considerati quando si esegue un ordinamento linguistico o con distinzione tra impostazioni cultura. In una ricerca dipendente dalle impostazioni cultura, se value contiene un carattere ignorabile, il risultato è equivalente alla ricerca con il carattere rimosso. Se value è costituito solo da uno o più caratteri ignorabili, il LastIndexOf(String, String, Int32) metodo restituisce startIndexsempre , ovvero la posizione del carattere in corrispondenza della quale inizia la ricerca. Nell'esempio seguente viene usato il LastIndexOf(String, String, Int32) metodo per trovare una sottostringa che include un trattino morbido (U+00AD) e che precede o include l'ultimo "m" in una stringa. Poiché il trattino morbido nella stringa di ricerca viene ignorato, chiamando il metodo per trovare una sottostringa costituita dal trattino morbido e "m" restituisce la posizione del "m" nella stringa, mentre chiamandola per trovare una sottostringa costituita dal trattino morbido e "n" restituisce la posizione del "n". Quando la stringa di ricerca contiene solo il trattino morbido, il metodo restituisce l'indice di "m", che rappresenta il valore di startIndex.

::code language="csharp" source="~/snippets/csharp/System.Globalization/CompareInfo/LastIndexOf/lastignorable6.cs" id="Snippet7"::: code language="vb" source="~/snippets/visualbasic/VS_Snippets_CLR_System/system.globalization.compareinfo.lastindexof/vb/lastignorable6.vb" id="Snippet7":::

Vedi anche

IndexOf(String, Char)

Si applica a