Gets whether cancellation has been requested for this token.
Assembly: mscorlib (in mscorlib.dll)
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.
If this property is true, it only guarantees that cancellation has been requested. It does not guarantee that every registered handler has finished executing, nor that cancellation requests have finished propagating to all registered handlers. Additional synchronization may be required, particularly in situations where related objects are being canceled concurrently.
The following is a simple example that executes a server process until theproperty returns true.
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.
Available since 8
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Available since 5.0
Windows Phone Silverlight
Available since 8.0
Available since 8.1