String.Intern(String) Metoda

Definicja

Przestrzeń nazw:

System

Zestawy:

netstandard.dll, System.Runtime.dll

Źródło:

String.CoreCLR.cs

Pobiera odwołanie systemu do określonego Stringelementu .

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

Parametry

str

String

Ciąg do wyszukania w puli internowej.

Zwraca

String

Odwołanie systemu do strmetody , jeśli jest internowane; w przeciwnym razie nowe odwołanie do ciągu o wartości str.

Wyjątki

ArgumentNullException

Parametr str ma wartość null.

Przykłady

Poniższy przykład tworzy dwa ciągi o równych wartościach i pokazuje, że ich przeplatanie daje to samo odwołanie.

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

class Sample
{
    public static void Main()
    {
        string s1 = new StringBuilder().Append("My").Append("Test").ToString();
        string s2 = new StringBuilder().Append("My").Append("Test").ToString();
        Console.WriteLine($"s1 == {s1}");
        Console.WriteLine($"s2 == {s2}");
        Console.WriteLine($"Are s1 and s2 equal in value? {s1 == s2}");
        Console.WriteLine($"Are s1 and s2 the same reference? {Object.ReferenceEquals(s1, s2)}");

        string i1 = String.Intern(s1);
        string i2 = String.Intern(s2);
        Console.WriteLine($"After interning:");
        Console.WriteLine($"  Are i1 and i2 equal in value? {i1 == i2}");
        Console.WriteLine($"  Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}");
    }
}
/*
This example produces the following results:
s1 == MyTest
s2 == MyTest
Are s1 and s2 equal in value? True
Are s1 and s2 the same reference? False
After interning:
  Are i1 and i2 equal in value? True
  Are i1 and i2 the same reference? True
*/

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

let s1 = StringBuilder().Append("My").Append("Test").ToString()
let s2 = StringBuilder().Append("My").Append("Test").ToString()
printfn $"s1 = {s1}"
printfn $"s2 = {s2}"
printfn $"Are s1 and s2 equal in value? {s1 = s2}"
printfn $"Are s1 and s2 the same reference? {Object.ReferenceEquals(s1, s2)}"

let i1 = String.Intern s1
let i2 = String.Intern s2
printfn "After interning:"
printfn $"  Are i1 and i2 equal in value? {i1 = i2}"
printfn $"  Are i1 and i2 the same reference? {Object.ReferenceEquals(i1, i2)}"
(*
This example produces the following results:
s1 = MyTest
s2 = MyTest
Are s1 and s2 equal in value? True
Are s1 and s2 the same reference? False
After interning:
  Are i1 and i2 equal in value? True
  Are i1 and i2 the same reference? True
*)

Imports System.Text

Class Sample

    Public Shared Sub Main()
        Dim s1 As String = New StringBuilder().Append("My").Append("Test").ToString()
        Dim s2 As String = New StringBuilder().Append("My").Append("Test").ToString()
        Console.WriteLine($"s1 = {s1}")
        Console.WriteLine($"s2 = {s2}")
        Console.WriteLine($"Are s1 and s2 equal in value? {s1 = s2}")
        Console.WriteLine($"Are s1 and s2 the same reference? {s1 Is s2}")

        Dim i1 As String = String.Intern(s1)
        Dim i2 As String = String.Intern(s2)
        Console.WriteLine("After interning:")
        Console.WriteLine($"  Are i1 and i2 equal in value? {i1 = i2}")
        Console.WriteLine($"  Are i1 and i2 the same reference? {i1 Is i2}")
    End Sub
End Class
'
's1 = MyTest
's2 = MyTest
'Are s1 and s2 equal in value? True
'Are s1 and s2 the same reference? False
'After interning:
'  Are i1 and i2 equal in value? True
'  Are i1 and i2 the same reference? True
'

Uwagi

! [UWAGA] Chociaż String.Intern gwarantuje, że dwa ciągi o równych wartościach zwracają to samo odwołanie internowane, nie gwarantuje, że zwrócone odwołanie jest takie samo jak literał ciągu.

Aby uzyskać więcej informacji na temat tego interfejsu API, zobacz Dodatkowe uwagi dotyczące interfejsu API dla metody String.Intern.

Zobacz też

• IsInterned(String)