String.Equals 方法

参考

定义

命名空间:: System

程序集:: System.Runtime.dll

程序集:: mscorlib.dll

程序集:: netstandard.dll

重要

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确定两个 String 对象是否具有相同的值。

重载

Equals(Object)	确定此实例是否与指定的对象（也必须是 String 对象）具有相同的值。
Equals(String)	确定此实例是否与另一个指定的 String 对象具有相同的值。
Equals(String, String)	确定两个指定的 String 对象是否具有相同的值。
Equals(String, StringComparison)	确定此字符串是否与另一个指定的 String 对象具有相同的值。参数指定区域性、大小写以及比较所用的排序规则。
Equals(String, String, StringComparison)	确定两个指定的 String 对象是否具有相同的值。参数指定区域性、大小写以及比较所用的排序规则。

Equals(Object)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

确定此实例是否与指定的对象（也必须是 String 对象）具有相同的值。

public:
 override bool Equals(System::Object ^ obj);

public override bool Equals (object obj);

public override bool Equals (object? obj);

override this.Equals : obj -> bool

Public Overrides Function Equals (obj As Object) As Boolean

参数

obj: Object

要与此实例进行比较的字符串。

Boolean

如果 true 是一个 obj 且其值与此实例相等，则为 String；否则为 false。如果 obj 为 null，则此方法返回 false。

示例

下面的示例演示 Equals 方法。

// Sample for String::Equals(Object)
//            String::Equals(String)
//            String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
   StringBuilder^ sb = gcnew StringBuilder( "abcd" );
   String^ str1 = "abcd";
   String^ str2 = nullptr;
   Object^ o2 = nullptr;
   Console::WriteLine();
   Console::WriteLine( " *  The value of String str1 is '{0}'.", str1 );
   Console::WriteLine( " *  The value of StringBuilder sb is '{0}'.", sb );
   Console::WriteLine();
   Console::WriteLine( "1a) String::Equals(Object). Object is a StringBuilder, not a String." );
   Console::WriteLine( "    Is str1 equal to sb?: {0}", str1->Equals( sb ) );
   Console::WriteLine();
   Console::WriteLine( "1b) String::Equals(Object). Object is a String." );
   str2 = sb->ToString();
   o2 = str2;
   Console::WriteLine( " *  The value of Object o2 is '{0}'.", o2 );
   Console::WriteLine( "    Is str1 equal to o2?: {0}", str1->Equals( o2 ) );
   Console::WriteLine();
   Console::WriteLine( " 2) String::Equals(String)" );
   Console::WriteLine( " *  The value of String str2 is '{0}'.", str2 );
   Console::WriteLine( "    Is str1 equal to str2?: {0}", str1->Equals( str2 ) );
   Console::WriteLine();
   Console::WriteLine( " 3) String::Equals(String, String)" );
   Console::WriteLine( "    Is str1 equal to str2?: {0}", String::Equals( str1, str2 ) );
}

/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String::Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String::Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String::Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String::Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample1
{
    public static void Main()
    {
        StringBuilder sb = new StringBuilder("abcd");
        String str1 = "abcd";
        String str2 = null;
        Object o2 = null;

        Console.WriteLine();
        Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
        Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString());

        Console.WriteLine();
        Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.");
        Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb));

        Console.WriteLine();
        Console.WriteLine("1b) String.Equals(Object). Object is a String.");
        str2 = sb.ToString();
        o2 = str2;
        Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
        Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2));

        Console.WriteLine();
        Console.WriteLine(" 2) String.Equals(String)");
        Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
        Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2));

        Console.WriteLine();
        Console.WriteLine(" 3) String.Equals(String, String)");
        Console.WriteLine("    Is str1 equal to str2?: {0}", String.Equals(str1, str2));
    }
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
open System
open System.Text

let sb = StringBuilder "abcd"
let str1 = "abcd"
let str2 = string sb
let o2: obj = str2

printfn $"""
*  The value of String str1 is '{str1}'.
*  The value of StringBuilder sb is '{sb}'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
Is str1 equal to sb?: {str1.Equals sb}"

1b) String.Equals(Object). Object is a String.
*  The value of Object o2 is '{o2}'.
Is str1 equal to o2?: {str1.Equals o2}

2) String.Equals(String)
*  The value of String str2 is '{str2}'.
Is str1 equal to str2?: {str1.Equals str2}

3) String.Equals(String, String)
Is str1 equal to str2?: {String.Equals(str1, str2)}"""
(*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*)

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb As New StringBuilder("abcd")
      Dim str1 As [String] = "abcd"
      Dim str2 As [String] = Nothing
      Dim o2 As [Object] = Nothing
      
      Console.WriteLine()
      Console.WriteLine(" *  The value of String str1 is '{0}'.", str1)
      Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString())
      
      Console.WriteLine()
      Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.")
      Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb))
      
      Console.WriteLine()
      Console.WriteLine("1b) String.Equals(Object). Object is a String.")
      str2 = sb.ToString()
      o2 = str2
      Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2)
      Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2))
      
      Console.WriteLine()
      Console.WriteLine(" 2) String.Equals(String)")
      Console.WriteLine(" *  The value of String str2 is '{0}'.", str2)
      Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2))
      
      Console.WriteLine()
      Console.WriteLine(" 3) String.Equals(String, String)")
      Console.WriteLine("    Is str1 equal to str2?: {0}", [String].Equals(str1, str2))
   End Sub
End Class
'
'This example produces the following results:
'
' *  The value of String str1 is 'abcd'.
' *  The value of StringBuilder sb is 'abcd'.
'
'1a) String.Equals(Object). Object is a StringBuilder, not a String.
'    Is str1 equal to sb?: False
'
'1b) String.Equals(Object). Object is a String.
' *  The value of Object o2 is 'abcd'.
'    Is str1 equal to o2?: True
'
' 2) String.Equals(String)
' *  The value of String str2 is 'abcd'.
'    Is str1 equal to str2?: True
'
' 3) String.Equals(String, String)
'    Is str1 equal to str2?: True
'

注解

此方法执行序号 (区分大小写和不区分区域性的) 比较。

另请参阅

适用于

Equals(String)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

确定此实例是否与另一个指定的 String 对象具有相同的值。

public:
 virtual bool Equals(System::String ^ value);

public:
 bool Equals(System::String ^ value);

public bool Equals (string value);

public bool Equals (string? value);

override this.Equals : string -> bool

Public Function Equals (value As String) As Boolean

参数

value: String

要与此实例进行比较的字符串。

Boolean

如果 true 参数的值与此实例的值相同，则为 value；否则为 false。如果 value 为 null，则此方法返回 false。

实现

Equals(T)

示例

下面的示例演示 Equals 方法。它将标题大小写单词“File”与等效字词、小写等效词、大写等效词和包含拉丁文小写字母 DOTLESS I (U+0131) 而不是拉丁文小写字母 I (U+0069) 进行比较。 Equals(String)由于方法执行序号比较，因此只有具有相同单词的比较返回 true。

using System;

public class Example
{
    public static void Main()
    {
        Console.OutputEncoding = System.Text.Encoding.UTF8;
        string word = "File";
        string[] others = { word.ToLower(), word, word.ToUpper(), "Fıle" };
        foreach (string other in others)
        {
            if (word.Equals(other))
                Console.WriteLine("{0} = {1}", word, other);
            else
                Console.WriteLine("{0} {1} {2}", word, '\u2260', other);
        }
    }
}
// The example displays the following output:
//       File ≠ file
//       File = File
//       File ≠ FILE
//       File ≠ Fıle

open System

Console.OutputEncoding <- Text.Encoding.UTF8
let word = "File"
let others = [| word.ToLower(); word; word.ToUpper(); "Fıle" |]
for other in others do
    if word.Equals other then
        printfn $"{word} = {other}"
    else
        printfn $"{word} \u2260 {other}"
// The example displays the following output:
//       File ≠ file
//       File = File
//       File ≠ FILE
//       File ≠ Fıle

Module Example
   Public Sub Main()
      Console.OutputEncoding = System.Text.Encoding.UTF8
      
      Dim word As String = "File"
      Dim others() As String = { word.ToLower(), word, word.ToUpper(), _
                                 "Fıle" }
      For Each other As String In others
         If word.Equals(other) Then 
            Console.WriteLine("{0} = {1}", word, other)
         Else
            Console.WriteLine("{0} {1} {2}", word, ChrW(&H2260), other)
         End If      
      Next        
   End Sub
End Module
' The example displays the following output:
'       File ≠ file
'       File = File
'       File ≠ FILE
'       File ≠ Fıle

注解

此方法执行序号 (区分大小写和不区分区域性的) 比较。

另请参阅

CompareOrdinal(String, String)

适用于

Equals(String, String)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

确定两个指定的 String 对象是否具有相同的值。

public:
 static bool Equals(System::String ^ a, System::String ^ b);

public static bool Equals (string a, string b);

public static bool Equals (string? a, string? b);

static member Equals : string * string -> bool

Public Shared Function Equals (a As String, b As String) As Boolean

参数

a: String

要比较的第一个字符串，或 null。

b: String

要比较的第二个字符串，或 null。

Boolean

如果 a 的值与 b 的值相同，则为 true；否则为 false。如果 a 和 b 均为 null，此方法将返回 true。

示例

下面的示例演示 Equals 方法。

// Sample for String::Equals(Object)
//            String::Equals(String)
//            String::Equals(String, String)
using namespace System;
using namespace System::Text;
int main()
{
   StringBuilder^ sb = gcnew StringBuilder( "abcd" );
   String^ str1 = "abcd";
   String^ str2 = nullptr;
   Object^ o2 = nullptr;
   Console::WriteLine();
   Console::WriteLine( " *  The value of String str1 is '{0}'.", str1 );
   Console::WriteLine( " *  The value of StringBuilder sb is '{0}'.", sb );
   Console::WriteLine();
   Console::WriteLine( "1a) String::Equals(Object). Object is a StringBuilder, not a String." );
   Console::WriteLine( "    Is str1 equal to sb?: {0}", str1->Equals( sb ) );
   Console::WriteLine();
   Console::WriteLine( "1b) String::Equals(Object). Object is a String." );
   str2 = sb->ToString();
   o2 = str2;
   Console::WriteLine( " *  The value of Object o2 is '{0}'.", o2 );
   Console::WriteLine( "    Is str1 equal to o2?: {0}", str1->Equals( o2 ) );
   Console::WriteLine();
   Console::WriteLine( " 2) String::Equals(String)" );
   Console::WriteLine( " *  The value of String str2 is '{0}'.", str2 );
   Console::WriteLine( "    Is str1 equal to str2?: {0}", str1->Equals( str2 ) );
   Console::WriteLine();
   Console::WriteLine( " 3) String::Equals(String, String)" );
   Console::WriteLine( "    Is str1 equal to str2?: {0}", String::Equals( str1, str2 ) );
}

/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String::Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String::Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String::Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String::Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
using System;
using System.Text;

class Sample1
{
    public static void Main()
    {
        StringBuilder sb = new StringBuilder("abcd");
        String str1 = "abcd";
        String str2 = null;
        Object o2 = null;

        Console.WriteLine();
        Console.WriteLine(" *  The value of String str1 is '{0}'.", str1);
        Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString());

        Console.WriteLine();
        Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.");
        Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb));

        Console.WriteLine();
        Console.WriteLine("1b) String.Equals(Object). Object is a String.");
        str2 = sb.ToString();
        o2 = str2;
        Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2);
        Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2));

        Console.WriteLine();
        Console.WriteLine(" 2) String.Equals(String)");
        Console.WriteLine(" *  The value of String str2 is '{0}'.", str2);
        Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2));

        Console.WriteLine();
        Console.WriteLine(" 3) String.Equals(String, String)");
        Console.WriteLine("    Is str1 equal to str2?: {0}", String.Equals(str1, str2));
    }
}
/*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*/

// Sample for String.Equals(Object)
//            String.Equals(String)
//            String.Equals(String, String)
open System
open System.Text

let sb = StringBuilder "abcd"
let str1 = "abcd"
let str2 = string sb
let o2: obj = str2

printfn $"""
*  The value of String str1 is '{str1}'.
*  The value of StringBuilder sb is '{sb}'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
Is str1 equal to sb?: {str1.Equals sb}"

1b) String.Equals(Object). Object is a String.
*  The value of Object o2 is '{o2}'.
Is str1 equal to o2?: {str1.Equals o2}

2) String.Equals(String)
*  The value of String str2 is '{str2}'.
Is str1 equal to str2?: {str1.Equals str2}

3) String.Equals(String, String)
Is str1 equal to str2?: {String.Equals(str1, str2)}"""
(*
This example produces the following results:

 *  The value of String str1 is 'abcd'.
 *  The value of StringBuilder sb is 'abcd'.

1a) String.Equals(Object). Object is a StringBuilder, not a String.
    Is str1 equal to sb?: False

1b) String.Equals(Object). Object is a String.
 *  The value of Object o2 is 'abcd'.
    Is str1 equal to o2?: True

 2) String.Equals(String)
 *  The value of String str2 is 'abcd'.
    Is str1 equal to str2?: True

 3) String.Equals(String, String)
    Is str1 equal to str2?: True
*)

' Sample for String.Equals(Object)
'            String.Equals(String)
'            String.Equals(String, String)
Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb As New StringBuilder("abcd")
      Dim str1 As [String] = "abcd"
      Dim str2 As [String] = Nothing
      Dim o2 As [Object] = Nothing
      
      Console.WriteLine()
      Console.WriteLine(" *  The value of String str1 is '{0}'.", str1)
      Console.WriteLine(" *  The value of StringBuilder sb is '{0}'.", sb.ToString())
      
      Console.WriteLine()
      Console.WriteLine("1a) String.Equals(Object). Object is a StringBuilder, not a String.")
      Console.WriteLine("    Is str1 equal to sb?: {0}", str1.Equals(sb))
      
      Console.WriteLine()
      Console.WriteLine("1b) String.Equals(Object). Object is a String.")
      str2 = sb.ToString()
      o2 = str2
      Console.WriteLine(" *  The value of Object o2 is '{0}'.", o2)
      Console.WriteLine("    Is str1 equal to o2?: {0}", str1.Equals(o2))
      
      Console.WriteLine()
      Console.WriteLine(" 2) String.Equals(String)")
      Console.WriteLine(" *  The value of String str2 is '{0}'.", str2)
      Console.WriteLine("    Is str1 equal to str2?: {0}", str1.Equals(str2))
      
      Console.WriteLine()
      Console.WriteLine(" 3) String.Equals(String, String)")
      Console.WriteLine("    Is str1 equal to str2?: {0}", [String].Equals(str1, str2))
   End Sub
End Class
'
'This example produces the following results:
'
' *  The value of String str1 is 'abcd'.
' *  The value of StringBuilder sb is 'abcd'.
'
'1a) String.Equals(Object). Object is a StringBuilder, not a String.
'    Is str1 equal to sb?: False
'
'1b) String.Equals(Object). Object is a String.
' *  The value of Object o2 is 'abcd'.
'    Is str1 equal to o2?: True
'
' 2) String.Equals(String)
' *  The value of String str2 is 'abcd'.
'    Is str1 equal to str2?: True
'
' 3) String.Equals(String, String)
'    Is str1 equal to str2?: True
'

注解

此方法执行序号 (区分大小写和不区分区域性的) 比较。

另请参阅

CompareOrdinal(String, String)

适用于

Equals(String, StringComparison)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

确定此字符串是否与另一个指定的 String 对象具有相同的值。参数指定区域性、大小写以及比较所用的排序规则。

public:
 bool Equals(System::String ^ value, StringComparison comparisonType);

public bool Equals (string value, StringComparison comparisonType);

public bool Equals (string? value, StringComparison comparisonType);

override this.Equals : string * StringComparison -> bool

Public Function Equals (value As String, comparisonType As StringComparison) As Boolean

参数

value: String

要与此实例进行比较的字符串。

comparisonType: StringComparison

枚举值之一，用于指定如何比较字符串。

Boolean

如果 true 参数的值与此字符串相同，则为 value；否则为 false。

例外

ArgumentException

comparisonType 不是 StringComparison 值。

示例

以下示例创建一个由大写“I”、小写“i”和无点“ı”组成的字符串数组。然后， Equals(String, StringComparison) 它调用方法以使用每个可能的 StringComparison 枚举值对其进行比较。

using System;

class Sample 
{
   public static void Main() 
   {
      // Define a string array with the following three "I" characters:
      //      U+0069, U+0131, and U+0049.  
      string[] threeIs = { "i", "ı", "I" };
      // Define Type object representing StringComparison type.
      Type scType = typeof(StringComparison);  
      
      // Show the current culture (for culture-sensitive string comparisons).
      Console.WriteLine("The current culture is {0}.\n", 
                        System.Globalization.CultureInfo.CurrentCulture.Name);
        
      // Perform comparisons using each StringComparison member. 
      foreach (string scName in Enum.GetNames(scType))
      {
         StringComparison sc = (StringComparison) Enum.Parse(scType, scName);
         Console.WriteLine("Comparisons using {0}:", sc);
         // Compare each character in character array.
         for (int ctr = 0; ctr <= 1; ctr++)
         {
            string instanceChar = threeIs[ctr];
            for (int innerCtr = ctr + 1; innerCtr <= threeIs.GetUpperBound(0); innerCtr++)
            {
               string otherChar = threeIs[innerCtr];
               Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", 
                                 instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), 
                                 otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), 
                                 instanceChar.Equals(otherChar, sc));
            }
            Console.WriteLine();
         }
      }   
   }
}
// The example displays the following output:
//       The current culture is en-US.
//       
//       Comparisons using CurrentCulture:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using CurrentCultureIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCulture:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCultureIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using Ordinal:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       ı (U+0131) = I (U+0049): False
//       
//       Comparisons using OrdinalIgnoreCase:
//       i (U+0069) = ı (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       ı (U+0131) = I (U+0049): False

open System
open System.Globalization

// Define a string array with the following three "I" characters:
//      U+0069, U+0131, and U+0049.  
let threeIs = [| "i"; "ı"; "I" |]
// Define Type object representing StringComparison type.
let scType = typeof<StringComparison>  

// Show the current culture (for culture-sensitive string comparisons).
printfn $"The current culture is {CultureInfo.CurrentCulture.Name}.\n"

// Perform comparisons using each StringComparison member. 
for scName in Enum.GetNames scType do
    let sc = Enum.Parse(scType, scName) :?> StringComparison
    printfn $"Comparisons using {sc}:"
    // Compare each character in character array.
    for ctr = 0 to 1 do
        let instanceChar = threeIs[ctr]
        for innerCtr = ctr + 1 to threeIs.GetUpperBound 0 do
            let otherChar = threeIs[innerCtr]
            printfn $"{instanceChar} (U+{Convert.ToInt16(Char.Parse instanceChar):X4}) = {otherChar} (U+{Convert.ToInt16(Char.Parse otherChar):X4}): {instanceChar.Equals(otherChar, sc)}"
        printfn ""
// The example displays the following output:
//       The current culture is en-US.
//       
//       Comparisons using CurrentCulture:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using CurrentCultureIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCulture:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using InvariantCultureIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using Ordinal:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): False
//       
//       i (U+0131) = I (U+0049): False
//       
//       Comparisons using OrdinalIgnoreCase:
//       i (U+0069) = i (U+0131): False
//       i (U+0069) = I (U+0049): True
//       
//       i (U+0131) = I (U+0049): False

Class Sample
   Public Shared Sub Main() 
      ' Define a string array with the following three "I" characters:
      '      U+0069, U+0131, and U+0049.  
      Dim threeIs() As String = { "i", "ı", "I" }
      ' Define Type object representing StringComparison type.
      Dim scType As Type = GetType(StringComparison)  
      
      ' Show the current culture (for culture-sensitive string comparisons).
      Console.WriteLine("The current culture is {0}." & vbCrLf, _
                        System.Globalization.CultureInfo.CurrentCulture.Name)
        
      ' Perform comparisons using each StringComparison member. 
      For Each scName As String In [Enum].GetNames(scType)
         Dim sc As StringComparison = [Enum].Parse(scType, scName)
         Console.WriteLine("Comparisons using {0}:", sc)
         ' Compare each character in character array.
         For ctr As Integer = 0 To 1
            Dim instanceChar As String = threeIs(ctr)
            For innerCtr As Integer = ctr + 1 To threeIs.GetUpperBound(0)
               Dim otherChar As STring = threeIs(innerCtr)
               Console.WriteLine("{0} (U+{1}) = {2} (U+{3}): {4}", _
                                 instanceChar, Convert.ToInt16(Char.Parse(instanceChar)).ToString("X4"), _
                                 otherChar, Convert.ToInt16(Char.Parse(otherChar)).ToString("X4"), _
                                 instanceChar.Equals(otherChar, sc))
            Next
            Console.WriteLine()
         Next
      Next              
   End Sub
End Class
' The example displays the following output:
'       The current culture is en-US.
'       
'       Comparisons using CurrentCulture:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using CurrentCultureIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using InvariantCulture:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using InvariantCultureIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using Ordinal:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): False
'       
'       i (U+0131) = I (U+0049): False
'       
'       Comparisons using OrdinalIgnoreCase:
'       i (U+0069) = i (U+0131): False
'       i (U+0069) = I (U+0049): True
'       
'       i (U+0131) = I (U+0049): False

注解

参数 comparisonType 指示比较是应使用当前区域性还是固定区域性、遵循或忽略要比较的两个字符串的事例，还是使用单词或序号排序规则。

另请参阅

CompareOrdinal(String, String)

适用于

Equals(String, String, StringComparison)

Source:: String.Comparison.cs

Source:: String.Comparison.cs

Source:: String.Comparison.cs

确定两个指定的 String 对象是否具有相同的值。参数指定区域性、大小写以及比较所用的排序规则。

public:
 static bool Equals(System::String ^ a, System::String ^ b, StringComparison comparisonType);

public static bool Equals (string a, string b, StringComparison comparisonType);

public static bool Equals (string? a, string? b, StringComparison comparisonType);

static member Equals : string * string * StringComparison -> bool

Public Shared Function Equals (a As String, b As String, comparisonType As StringComparison) As Boolean

参数

a: String

要比较的第一个字符串，或 null。

b: String

要比较的第二个字符串，或 null。

comparisonType: StringComparison

枚举值之一，用于指定比较的规则。

Boolean

如果 true 参数的值与 a 参数的值相同，则为 b；否则为 false。

例外

ArgumentException

comparisonType 不是 StringComparison 值。

示例

以下示例使用枚举的每个成员 StringComparison 比较三组字符串。比较使用英语 (美国) 、泰语 (泰国) 和土耳其 (土耳其) 文化的约定。请注意，字符串“a”和“a-”在“th-TH”区域性中被视为等效，但在其他区域性中则不相等，而在“tr-TR”区域性中，当大小写被忽略但不在其他区域性中，则“i”和“İ”被视为等效。

using System;
using System.Globalization;
using System.Threading;

public class Example3
{
    public static void Main()
    {
        String[] cultureNames = { "en-US", "th-TH", "tr-TR" };
        String[] strings1 = { "a", "i", "case", };
        String[] strings2 = { "a-", "\u0130", "Case" };
        StringComparison[] comparisons = (StringComparison[])Enum.GetValues(typeof(StringComparison));

        foreach (var cultureName in cultureNames)
        {
            Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName);
            Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name);
            for (int ctr = 0; ctr <= strings1.GetUpperBound(0); ctr++)
            {
                foreach (var comparison in comparisons)
                    Console.WriteLine("   {0} = {1} ({2}): {3}", strings1[ctr],
                                      strings2[ctr], comparison,
                                      String.Equals(strings1[ctr], strings2[ctr], comparison));

                Console.WriteLine();
            }
            Console.WriteLine();
        }
    }
}
// The example displays the following output:
//    Current Culture: en-US
//       a = a- (CurrentCulture): False
//       a = a- (CurrentCultureIgnoreCase): False
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): False
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//
//
//    Current Culture: th-TH
//       a = a- (CurrentCulture): True
//       a = a- (CurrentCultureIgnoreCase): True
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): False
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//
//
//    Current Culture: tr-TR
//       a = a- (CurrentCulture): False
//       a = a- (CurrentCultureIgnoreCase): False
//       a = a- (InvariantCulture): False
//       a = a- (InvariantCultureIgnoreCase): False
//       a = a- (Ordinal): False
//       a = a- (OrdinalIgnoreCase): False
//
//       i = İ (CurrentCulture): False
//       i = İ (CurrentCultureIgnoreCase): True
//       i = İ (InvariantCulture): False
//       i = İ (InvariantCultureIgnoreCase): False
//       i = İ (Ordinal): False
//       i = İ (OrdinalIgnoreCase): False
//
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True

open System
open System.Globalization
open System.Threading

let cultureNames = 
    [| "en-US"; "se-SE" |]
let strings1 = 
    [| "case"; "encyclopædia" 
       "encyclopædia"; "Archæology" |]
let strings2 = 
    [| "Case"; "encyclopaedia" 
       "encyclopedia"; "ARCHÆOLOGY" |]
let comparisons = 
    Enum.GetValues typeof<StringComparison> :?> StringComparison[]

for cultureName in cultureNames do
    Thread.CurrentThread.CurrentCulture <- CultureInfo.CreateSpecificCulture cultureName
    printfn $"Current Culture: {CultureInfo.CurrentCulture.Name}"
    for i = 0 to strings1.GetUpperBound 0 do
        for comparison in comparisons do
            printfn $"   {strings1[i]} = {strings2[i]} ({comparison}): {String.Equals(strings1[i], strings2[i], comparison)}"
        printfn ""         
    printfn ""
// The example displays the following output:
//    Current Culture: en-US
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//    
//       encyclopædia = encyclopaedia (CurrentCulture): True
//       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
//       encyclopædia = encyclopaedia (InvariantCulture): True
//       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
//       encyclopædia = encyclopaedia (Ordinal): False
//       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//    
//       encyclopædia = encyclopedia (CurrentCulture): False
//       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
//       encyclopædia = encyclopedia (InvariantCulture): False
//       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
//       encyclopædia = encyclopedia (Ordinal): False
//       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//    
//       Archæology = ARCHÆOLOGY (CurrentCulture): False
//       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (InvariantCulture): False
//       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (Ordinal): False
//       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
//    
//    
//    Current Culture: se-SE
//       case = Case (CurrentCulture): False
//       case = Case (CurrentCultureIgnoreCase): True
//       case = Case (InvariantCulture): False
//       case = Case (InvariantCultureIgnoreCase): True
//       case = Case (Ordinal): False
//       case = Case (OrdinalIgnoreCase): True
//    
//       encyclopædia = encyclopaedia (CurrentCulture): False
//       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
//       encyclopædia = encyclopaedia (InvariantCulture): True
//       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
//       encyclopædia = encyclopaedia (Ordinal): False
//       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
//    
//       encyclopædia = encyclopedia (CurrentCulture): False
//       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
//       encyclopædia = encyclopedia (InvariantCulture): False
//       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
//       encyclopædia = encyclopedia (Ordinal): False
//       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
//    
//       Archæology = ARCHÆOLOGY (CurrentCulture): False
//       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (InvariantCulture): False
//       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
//       Archæology = ARCHÆOLOGY (Ordinal): False
//       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True

Imports System.Globalization
Imports System.Threading

Module Example
   Public Sub Main()
      Dim cultureNames() As String = { "en-US", "se-SE" }
      Dim strings1() As String = { "case",  "encyclopædia",  
                                   "encyclopædia", "Archæology" }
      Dim strings2() As String = { "Case", "encyclopaedia", 
                                   "encyclopedia" , "ARCHÆOLOGY" }
      Dim comparisons() As StringComparison = CType([Enum].GetValues(GetType(StringComparison)),
                                           StringComparison())
      
      For Each cultureName In cultureNames
         Thread.CurrentThread.CurrentCulture = CultureInfo.CreateSpecificCulture(cultureName)
         Console.WriteLine("Current Culture: {0}", CultureInfo.CurrentCulture.Name)
         For ctr As Integer = 0 To strings1.GetUpperBound(0)
            For Each comparison In comparisons
               Console.WriteLine("   {0} = {1} ({2}): {3}", strings1(ctr),
                                 strings2(ctr), comparison, 
                                 String.Equals(strings1(ctr), strings2(ctr), comparison))
            Next
            Console.WriteLine()         
         Next
         Console.WriteLine()
      Next
   End Sub
End Module
' The example displays the following output:
'    Current Culture: en-US
'       case = Case (CurrentCulture): False
'       case = Case (CurrentCultureIgnoreCase): True
'       case = Case (InvariantCulture): False
'       case = Case (InvariantCultureIgnoreCase): True
'       case = Case (Ordinal): False
'       case = Case (OrdinalIgnoreCase): True
'    
'       encyclopædia = encyclopaedia (CurrentCulture): True
'       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): True
'       encyclopædia = encyclopaedia (InvariantCulture): True
'       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
'       encyclopædia = encyclopaedia (Ordinal): False
'       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'    
'       encyclopædia = encyclopedia (CurrentCulture): False
'       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
'       encyclopædia = encyclopedia (InvariantCulture): False
'       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
'       encyclopædia = encyclopedia (Ordinal): False
'       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'    
'       Archæology = ARCHÆOLOGY (CurrentCulture): False
'       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (InvariantCulture): False
'       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (Ordinal): False
'       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True
'    
'    
'    Current Culture: se-SE
'       case = Case (CurrentCulture): False
'       case = Case (CurrentCultureIgnoreCase): True
'       case = Case (InvariantCulture): False
'       case = Case (InvariantCultureIgnoreCase): True
'       case = Case (Ordinal): False
'       case = Case (OrdinalIgnoreCase): True
'    
'       encyclopædia = encyclopaedia (CurrentCulture): False
'       encyclopædia = encyclopaedia (CurrentCultureIgnoreCase): False
'       encyclopædia = encyclopaedia (InvariantCulture): True
'       encyclopædia = encyclopaedia (InvariantCultureIgnoreCase): True
'       encyclopædia = encyclopaedia (Ordinal): False
'       encyclopædia = encyclopaedia (OrdinalIgnoreCase): False
'    
'       encyclopædia = encyclopedia (CurrentCulture): False
'       encyclopædia = encyclopedia (CurrentCultureIgnoreCase): False
'       encyclopædia = encyclopedia (InvariantCulture): False
'       encyclopædia = encyclopedia (InvariantCultureIgnoreCase): False
'       encyclopædia = encyclopedia (Ordinal): False
'       encyclopædia = encyclopedia (OrdinalIgnoreCase): False
'    
'       Archæology = ARCHÆOLOGY (CurrentCulture): False
'       Archæology = ARCHÆOLOGY (CurrentCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (InvariantCulture): False
'       Archæology = ARCHÆOLOGY (InvariantCultureIgnoreCase): True
'       Archæology = ARCHÆOLOGY (Ordinal): False
'       Archæology = ARCHÆOLOGY (OrdinalIgnoreCase): True

注解

参数 comparisonType 指示比较是应使用当前区域性还是固定区域性、遵循或忽略要比较的两个字符串的事例，还是使用单词或序号排序规则。

另请参阅

CompareOrdinal(String, String)

适用于

通过

String.Equals 方法

定义

重载

Equals(Object)

参数

返回

示例

注解

另请参阅

适用于

Equals(String)

参数

返回

实现

示例

注解

另请参阅

适用于

Equals(String, String)

参数

返回

示例

注解

另请参阅

适用于

Equals(String, StringComparison)

参数

返回

例外

示例

注解

另请参阅

适用于

Equals(String, String, StringComparison)

参数

返回

例外

示例

注解

另请参阅

适用于

其他资源