String.IsInterned(String) Yöntem

Tanım

Ad Alanı:

System

Bütünleştirilmiş Kod:

System.Runtime.dll

Source:

String.CoreCLR.cs

Belirtilen Stringöğesine başvuru alır.

public:
 static System::String ^ IsInterned(System::String ^ str);

public static string? IsInterned (string str);

static member IsInterned : string -> string

Public Shared Function IsInterned (str As String) As String

Parametreler

str

String

Stajyer havuzunda aranacak dize.

Döndürülenler

String

str Ortak dil çalışma zamanı stajyer havuzundaysa başvurusu; değilse, null.

Özel durumlar

ArgumentNullException

str, null değeridir.

Örnekler

Aşağıdaki örnek, değişmez dizelerin derleyici tarafından otomatik olarak interned olduğunu gösterir.

// Sample for String::IsInterned(String)
using namespace System;
using namespace System::Text;
using namespace System::Runtime::CompilerServices;

// In the .NET Framework 2.0 the following attribute declaration allows you to 
// avoid the use of the interning when you use NGEN.exe to compile an assembly 
// to the native image cache.
[assembly:CompilationRelaxations(CompilationRelaxations::NoStringInterning)];
void Test( int sequence, String^ str )
{
   Console::Write( "{0} The string '", sequence );
   String^ strInterned = String::IsInterned( str );
   if ( strInterned == nullptr )
      Console::WriteLine( "{0}' is not interned.", str );
   else
      Console::WriteLine( "{0}' is interned.", strInterned );
}

int main()
{
   
   // String str1 is known at compile time, and is automatically interned.
   String^ str1 = "abcd";
   
   // Constructed string, str2, is not explicitly or automatically interned.
   String^ str2 = (gcnew StringBuilder)->Append( "wx" )->Append( "yz" )->ToString();
   Console::WriteLine();
   Test( 1, str1 );
   Test( 2, str2 );
}

//This example produces the following results:

//1) The string, 'abcd', is interned.
//2) The string, 'wxyz', is not interned.

//If you use NGEN.exe to compile the assembly to the native image cache, this
//example produces the following results:

//1) The string, 'abcd', is not interned.
//2) The string, 'wxyz', is not interned.

// Sample for String.IsInterned(String)
using System;
using System.Text;
using System.Runtime.CompilerServices;

// In the .NET Framework 2.0 the following attribute declaration allows you to
// avoid the use of the interning when you use NGEN.exe to compile an assembly
// to the native image cache.
[assembly: CompilationRelaxations(CompilationRelaxations.NoStringInterning)]
class Sample
{
    public static void Main()
    {
        // String str1 is known at compile time, and is automatically interned.
        String str1 = "abcd";

        // Constructed string, str2, is not explicitly or automatically interned.
        String str2 = new StringBuilder().Append("wx").Append("yz").ToString();
        Console.WriteLine();
        Test(1, str1);
        Test(2, str2);
    }

    public static void Test(int sequence, String str)
    {
        Console.Write("{0}) The string, '", sequence);
        String strInterned = String.IsInterned(str);
        if (strInterned == null)
            Console.WriteLine("{0}', is not interned.", str);
        else
            Console.WriteLine("{0}', is interned.", strInterned);
    }
}

//This example produces the following results:

//1) The string, 'abcd', is interned.
//2) The string, 'wxyz', is not interned.

//If you use NGEN.exe to compile the assembly to the native image cache, this
//example produces the following results:

//1) The string, 'abcd', is not interned.
//2) The string, 'wxyz', is not interned.

// Sample for String.IsInterned(String)
open System
open System.Text
open System.Runtime.CompilerServices

// In the .NET Framework 2.0 the following attribute declaration allows you to
// avoid the use of the interning when you use NGEN.exe to compile an assembly
// to the native image cache.
[<assembly: CompilationRelaxations(CompilationRelaxations.NoStringInterning)>]
do ()

let test sequence str =
    printf $"%d{sequence}) The string, '"
    let strInterned = String.IsInterned str
    if isNull strInterned then
        printfn $"{str}', is not interned."
    else
        printfn $"{strInterned}', is interned."

// String str1 is known at compile time, and is automatically interned.
let str1 = "abcd"

// Constructed string, str2, is not explicitly or automatically interned.
let str2 = StringBuilder().Append("wx").Append("yz").ToString()
printfn ""
test 1 str1
test 2 str2


//This example produces the following results:

//1) The string, 'abcd', is interned.
//2) The string, 'wxyz', is not interned.

//If you use NGEN.exe to compile the assembly to the native image cache, this
//example produces the following results:

//1) The string, 'abcd', is not interned.
//2) The string, 'wxyz', is not interned.

' Sample for String.IsInterned(String)
Imports System.Text
Imports System.Runtime.CompilerServices

' In the .NET Framework 2.0 the following attribute declaration allows you to 
' avoid the use of the interning when you use NGEN.exe to compile an assembly 
' to the native image cache.
<Assembly: CompilationRelaxations(CompilationRelaxations.NoStringInterning)> 
Class Sample
    Public Shared Sub Main()
        ' String str1 is known at compile time, and is automatically interned.
        Dim str1 As [String] = "abcd"

        ' Constructed string, str2, is not explicitly or automatically interned.
        Dim str2 As [String] = New StringBuilder().Append("wx").Append("yz").ToString()
        Console.WriteLine()
        Test(1, str1)
        Test(2, str2)
    End Sub

    Public Shared Sub Test(ByVal sequence As Integer, ByVal str As [String])
        Console.Write("{0}) The string, '", sequence)
        Dim strInterned As [String] = [String].IsInterned(str)
        If strInterned Is Nothing Then
            Console.WriteLine("{0}', is not interned.", str)
        Else
            Console.WriteLine("{0}', is interned.", strInterned)
        End If
    End Sub
End Class

'This example produces the following results:

'1) The string, 'abcd', is interned.
'2) The string, 'wxyz', is not interned.

'If you use NGEN.exe to compile the assembly to the native image cache, this
'example produces the following results:

'1) The string, 'abcd', is not interned.
'2) The string, 'wxyz', is not interned.

Açıklamalar

Ortak dil çalışma zamanı, bir programda bildirilen her benzersiz değişmez dize sabitinin tek bir örneğini ve yöntemini çağırarak Intern program aracılığıyla eklediğiniz herhangi bir benzersiz örneğini String içeren, intern havuzu olarak adlandırılan bir tabloyu otomatik olarak tutar.

Stajyer havuzu dize depolama alanını korur. Çeşitli değişkenlere değişmez dize sabiti atarsanız, her değişken aynı değerlere sahip olan birkaç farklı örneğine String başvurmak yerine stajyer havuzundaki aynı sabite başvurmak üzere ayarlanır.

Bu yöntem stajyer havuzunda arar str . Zaten staj yapıldıysa str , bu örneğe bir başvuru döndürülür; aksi takdirde döndürülür null .

Bu yöntemi yöntemiyle karşılaştırın Intern .

Bu yöntem boole değeri döndürmez. Belirli bir dizenin interned olup olmadığını belirten bir Boole değeri istediğiniz için yöntemini çağırırsanız, aşağıdaki gibi bir kod kullanabilirsiniz.

using System;

public class Example
{
   public static void Main()
   {
      string str1 = "a";
      string str2 = str1 + "b";
      string str3 = str2 + "c";
      string[] strings = { "value", "part1" + "_" + "part2", str3, 
                           String.Empty, null };
      foreach (var value in strings) {
         if (value == null) continue;
         
         bool interned = String.IsInterned(value) != null;
         if (interned)
            Console.WriteLine("'{0}' is in the string intern pool.", 
                              value);
         else
            Console.WriteLine("'{0}' is not in the string intern pool.",
                              value);                      
      }
   }
}
// The example displays the following output:
//       'value' is in the string intern pool.
//       'part1_part2' is in the string intern pool.
//       'abc' is not in the string intern pool.
//       '' is in the string intern pool.

open System

let str1 = "a"
let str2 = str1 + "b"
let str3 = str2 + "c"
let strings = 
    [| "value"; "part1" + "_" + "part2"; str3
       String.Empty; null |]
for value in strings do
    if value <> null then
        let interned = String.IsInterned(value) <> null
        if interned then
            printfn $"'{value}' is in the string intern pool."
        else
            printfn $"'{value}' is not in the string intern pool."
// The example displays the following output:
//       'value' is in the string intern pool.
//       'part1_part2' is in the string intern pool.
//       'abc' is not in the string intern pool.
//       '' is in the string intern pool.

Module Example
   Public Sub Main()
      Dim str1 As String = "a"
      Dim str2 As String = str1 + "b"
      Dim str3 As String = str2 + "c"
      Dim strings() As String = { "value", "part1" + "_" + "part2", str3, 
                                  String.Empty, Nothing }
      For Each value In strings
         If value Is Nothing Then Continue For
         
         Dim interned As Boolean = (String.IsInterned(value) IsNot Nothing)
         If interned Then
            Console.WriteLine("'{0}' is in the string intern pool.", 
                              value)
         Else
            Console.WriteLine("'{0}' is not in the string intern pool.",
                              value)                      
         End If
      Next
   End Sub
End Module
' The example displays the following output:
'       'value' is in the string intern pool.
'       'part1_part2' is in the string intern pool.
'       'abc' is not in the string intern pool.
'       '' is in the string intern pool.

Not

Yerel bilgisayardaki yerel görüntü önbelleğine bir derleme yüklemek için Ngen.exe (Yerel Görüntü Oluşturucu) kullanırken stajyer havuzunun kullanımını geçersiz kılabilirsiniz. Daha fazla bilgi için Intern özelliğin Açıklamalar bölümündeki Performansla İlgili Dikkat Edilmesi Gerekenler bölümüne bakın.

Ayrıca bkz.

• Intern(String)