BackgroundWorker.CancellationPending Property

Gets a value indicating whether the application has requested cancellation of a background operation.

Namespace:  System.ComponentModel
Assembly:  System (in System.dll)

[BrowsableAttribute(false)]
public bool CancellationPending { get; }

Property Value

Type: System.Boolean
true if the application has requested cancellation of a background operation; otherwise, false. The default is false.

If CancellationPending is true, then the CancelAsync method has been called on the BackgroundWorker.

This property is meant for use by the worker thread, which should periodically check CancellationPending and abort the background operation when it is set to true.

The following code example demonstrates the use of the CancellationPending property to query a BackgroundWorker about its cancellation state. This code example is part of a larger example provided for the BackgroundWorker class.


// Abort the operation if the user has canceled.
// Note that a call to CancelAsync may have set 
// CancellationPending to true just after the
// last invocation of this method exits, so this 
// code will not have the opportunity to set the 
// DoWorkEventArgs.Cancel flag to true. This means
// that RunWorkerCompletedEventArgs.Cancelled will
// not be set to true in your RunWorkerCompleted
// event handler. This is a race condition.

if (worker.CancellationPending)
{   
    e.Cancel = true;
}
else
{   
    if (n < 2)
    {   
        result = 1;
    }
    else
    {   
        result = ComputeFibonacci(n - 1, worker, e) + 
                 ComputeFibonacci(n - 2, worker, e);
    }

    // Report progress as a percentage of the total task.
    int percentComplete = 
        (int)((float)n / (float)numberToCompute * 100);
    if (percentComplete > highestPercentageReached)
    {
        highestPercentageReached = percentComplete;
        worker.ReportProgress(percentComplete);
    }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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