String.Intern(String) 方法

定义

命名空间:

System

程序集:

System.Runtime.dll

Source:

String.CoreCLR.cs

检索系统对指定 String 的引用。

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

public static string Intern (string str);

static member Intern : string -> string

Public Shared Function Intern (str As String) As String

参数

str

String

要在暂存池中搜索的字符串。

返回

String

如果暂存了 str，则返回系统对其的引用；否则返回对值为 str 的字符串的新引用。

例外

ArgumentNullException

str 为 null。

示例

以下示例使用三个值相等的字符串来确定新创建的字符串和一个内联字符串是否相等。

// Sample for String::Intern(String)
using namespace System;
using namespace System::Text;
int main()
{
   String^ s1 = "MyTest";
   String^ s2 = (gcnew StringBuilder)->Append( "My" )->Append( "Test" )->ToString();
   String^ s3 = String::Intern( s2 );
   Console::WriteLine( "s1 == '{0}'", s1 );
   Console::WriteLine( "s2 == '{0}'", s2 );
   Console::WriteLine( "s3 == '{0}'", s3 );
   Console::WriteLine( "Is s2 the same reference as s1?: {0}", s2 == s1 );
   Console::WriteLine( "Is s3 the same reference as s1?: {0}", s3 == s1 );
}

/*
This example produces the following results:
s1 == 'MyTest'
s2 == 'MyTest'
s3 == 'MyTest'
Is s2 the same reference as s1?: False
Is s3 the same reference as s1?: True
*/

// Sample for String.Intern(String)
using System;
using System.Text;

class Sample
{
    public static void Main()
    {
        string s1 = "MyTest";
        string s2 = new StringBuilder().Append("My").Append("Test").ToString();
        string s3 = String.Intern(s2);
        Console.WriteLine($"s1 == {s1}");
        Console.WriteLine($"s2 == {s2}");
        Console.WriteLine($"s3 == {s3}");
        Console.WriteLine($"Is s2 the same reference as s1?: {(Object)s2 == (Object)s1}");
        Console.WriteLine($"Is s3 the same reference as s1?: {(Object)s3 == (Object)s1}");
    }
}
/*
This example produces the following results:
s1 == MyTest
s2 == MyTest
s3 == MyTest
Is s2 the same reference as s1?: False
Is s3 the same reference as s1?: True
*/

// Sample for String.Intern(String)
open System
open System.Text

let s1 = "MyTest"
let s2 = StringBuilder().Append("My").Append("Test").ToString()
let s3 = String.Intern s2
printfn $"s1 = {s1}"
printfn $"s2 = {s2}"
printfn $"s3 = {s3}"
printfn $"Is s2 the same reference as s1?: {s2 :> obj = s1 :> obj}"
printfn $"Is s3 the same reference as s1?: {s3 :> obj = s1 :> obj}"
(*
This example produces the following results:
s1 = MyTest
s2 = MyTest
s3 = MyTest
Is s2 the same reference as s1?: False
Is s3 the same reference as s1?: True
*)

Imports System.Text

Class Sample

    Public Shared Sub Main()
        Dim s1 As String = "MyTest"
        Dim s2 As String = New StringBuilder().Append("My").Append("Test").ToString()
        Dim s3 As String = String.Intern(s2)
        Console.WriteLine($"s1 = {s1}")
        Console.WriteLine($"s2 = {s2}")
        Console.WriteLine($"s3 = {s3}")
        Console.WriteLine($"Is s2 the same reference as s1?: {s2 Is s1}")
        Console.WriteLine($"Is s3 the same reference as s1?: {s3 Is s1}")
    End Sub
End Class
'
's1 = MyTest
's2 = MyTest
's3 = MyTest
'Is s2 the same reference as s1?: False
'Is s3 the same reference as s1?: True
'

注解

有关此 API 的详细信息，请参阅 String.Intern 的补充 API 备注。

另请参阅

• IsInterned(String)