CancellationToken.IsCancellationRequested 속성

정의

이 토큰의 취소가 요청되었는지 여부를 가져옵니다.Gets whether cancellation has been requested for this token.

public:
 property bool IsCancellationRequested { bool get(); };
public bool IsCancellationRequested { get; }
member this.IsCancellationRequested : bool
Public ReadOnly Property IsCancellationRequested As Boolean

속성 값

이 토큰에 대해 취소가 요청되었으며 true이고, 그러지 않으면 false입니다.true if cancellation has been requested for this token; otherwise, false.

예제

다음은 될 때까지 서버 프로세스를 실행 하는 간단한 예는 IsCancellationRequested 속성이 반환 true합니다.The following is a simple example that executes a server process until the IsCancellationRequested property returns true.

using System;
using System.Threading;

public class ServerClass
{
   public static void StaticMethod(object obj)
   {
      CancellationToken ct = (CancellationToken)obj;
      Console.WriteLine("ServerClass.StaticMethod is running on another thread.");

      // Simulate work that can be canceled.
      while (!ct.IsCancellationRequested) {
         Thread.SpinWait(50000);
      }
      Console.WriteLine("The worker thread has been canceled. Press any key to exit.");
      Console.ReadKey(true);
   }
}

public class Simple
{
   public static void Main()
   {
      // The Simple class controls access to the token source.
      CancellationTokenSource cts = new CancellationTokenSource();

      Console.WriteLine("Press 'C' to terminate the application...\n");
      // Allow the UI thread to capture the token source, so that it
      // can issue the cancel command.
      Thread t1 = new Thread(() => { if (Console.ReadKey(true).KeyChar.ToString().ToUpperInvariant() == "C")
                                     cts.Cancel(); } );

      // ServerClass sees only the token, not the token source.
      Thread t2 = new Thread(new ParameterizedThreadStart(ServerClass.StaticMethod));
      // Start the UI thread.

      t1.Start();

      // Start the worker thread and pass it the token.
      t2.Start(cts.Token);

      t2.Join();
      cts.Dispose();
   }
}
// The example displays the following output:
//       Press 'C' to terminate the application...
//
//       ServerClass.StaticMethod is running on another thread.
//       The worker thread has been canceled. Press any key to exit.
Imports System.Threading

Public Class ServerClass
   Public Shared Sub StaticMethod(obj As Object)
      Dim ct AS CancellationToken = CType(obj, CancellationToken)
      Console.WriteLine("ServerClass.StaticMethod is running on another thread.")

      ' Simulate work that can be canceled.
      While Not ct.IsCancellationRequested
         Thread.SpinWait(50000)
      End While
      Console.WriteLine("The worker thread has been canceled. Press any key to exit.")
      Console.ReadKey(True)
   End Sub
End Class

Public Class Simple
   Public Shared Sub Main()
      ' The Simple class controls access to the token source.
      Dim cts As New CancellationTokenSource()

      Console.WriteLine("Press 'C' to terminate the application..." + vbCrLf)
      ' Allow the UI thread to capture the token source, so that it
      ' can issue the cancel command.
      Dim t1 As New Thread( Sub()
                               If Console.ReadKey(true).KeyChar.ToString().ToUpperInvariant() = "C" Then
                                  cts.Cancel()
                               End If
                            End Sub)

      ' ServerClass sees only the token, not the token source.
      Dim t2 As New Thread(New ParameterizedThreadStart(AddressOf ServerClass.StaticMethod))

      ' Start the UI thread.
      t1.Start()

      ' Start the worker thread and pass it the token.
      t2.Start(cts.Token)

      t2.Join()
      cts.Dispose()
   End Sub
End Class
' The example displays the following output:
'       Press 'C' to terminate the application...
'
'       ServerClass.StaticMethod is running on another thread.
'       The worker thread has been canceled. Press any key to exit.

이 예제에서는 인스턴스화합니다는 CancellationTokenSource 취소 토큰에 대 한 액세스를 제어 하는 개체입니다.The example instantiates a CancellationTokenSource object, which controls access to the cancellation token. 다음 두 개의 스레드 프로시저를 정의합니다.It then defines two thread procedures. 키보드를 풀 하 고 "C" 키를 누를 때 호출 하는 람다 식으로 정의 된 첫 번째 CancellationTokenSource.Cancel 취소 토큰이 취소 된 상태로 설정 합니다.The first is defined as a lambda expression that pools the keyboard and, when the "C" key is pressed, calls CancellationTokenSource.Cancel to set the cancellation token to the cancelled state. 두 번째 매개 변수가 있는 메서드인지 ServerClass.StaticMethod, 될 때까지 루프를 실행 하는 IsCancellationRequested 속성은 true합니다.The second is a parameterized method, ServerClass.StaticMethod, that executes a loop until the IsCancellationRequested property is true.

주 스레드가 시작한 블록이 고 두 개의 스레드를 실행 하는 스레드가 될 때까지 ServerClass.StaticMethod 메서드를 종료 합니다.The main thread then starts the two threads and blocks until the thread that executes the ServerClass.StaticMethod method terminates.

설명

이 속성을 호출 하거나 처음에 취소 된 상태로 생성 되는 토큰을 통해이 토큰의 취소가 요청 되었는지 여부를 나타냅니다 Cancel 에 연결 된 토큰의 CancellationTokenSource합니다.This property indicates whether cancellation has been requested for this token, either through the token initially being constructed in a canceled state, or through calling Cancel on the token's associated CancellationTokenSource.

이 속성이 true, 취소가 요청 되었는지만 보장 합니다.If this property is true, it only guarantees that cancellation has been requested. 모든 등록 된 처리기가 실행을 완료 하거나 취소 요청 모든 등록 된 처리기에 완전히 전파 완료를 보장 하지 않습니다.It does not guarantee that every registered handler has finished executing, nor that cancellation requests have finished propagating to all registered handlers. 추가 동기화 관련된 개체를 동시에 취소 되는 위치는 상황에서 특히 필요할 수 있습니다.Additional synchronization may be required, particularly in situations where related objects are being canceled concurrently.

적용 대상

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