OnProgressChanged Method
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BackgroundWorker.OnProgressChanged Method

Raises the ProgressChanged event.

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

protected virtual void OnProgressChanged(
	ProgressChangedEventArgs e
)

Parameters

e
Type: System.ComponentModel.ProgressChangedEventArgs

An EventArgs that contains the event data.

Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.

The OnProgressChanged method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

Notes to Inheritors:

When overriding OnProgressChanged in a derived class, be sure to call the base class's OnProgressChanged method so that registered delegates receive the event.

The following code example demonstrates the use of the OnProgressChanged method to report the progress of an asynchronous operation. This code example is part of a larger example provided for the AsyncOperationManager class.

// This method is invoked via the AsyncOperation object, 
// so it is guaranteed to be executed on the correct thread. 
private void CalculateCompleted(object operationState)
{
    CalculatePrimeCompletedEventArgs e =
        operationState as CalculatePrimeCompletedEventArgs;

    OnCalculatePrimeCompleted(e);
}

// This method is invoked via the AsyncOperation object, 
// so it is guaranteed to be executed on the correct thread. 
private void ReportProgress(object state)
{
    ProgressChangedEventArgs e =
        state as ProgressChangedEventArgs;

    OnProgressChanged(e);
}

protected void OnCalculatePrimeCompleted(
    CalculatePrimeCompletedEventArgs e)
{
    if (CalculatePrimeCompleted != null)
    {
        CalculatePrimeCompleted(this, e);
    }
}

protected void OnProgressChanged(ProgressChangedEventArgs e)
{
    if (ProgressChanged != null)
    {
        ProgressChanged(e);
    }
}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0

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