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RunWorkerCompletedEventHandler Delegate

Represents the method that will handle the RunWorkerCompleted event of a BackgroundWorker class.

Namespace:  System.ComponentModel
Assembly:  System (in System.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)]
public delegate void RunWorkerCompletedEventHandler(
	Object sender,
	RunWorkerCompletedEventArgs e
)

Parameters

sender
Type: System.Object

The source of the event.

e
Type: System.ComponentModel.RunWorkerCompletedEventArgs

A RunWorkerCompletedEventArgs that contains the event data.

NoteNote:

The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: SharedState. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.

When you create a RunWorkerCompletedEventHandler delegate, you identify a method to handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see Events and Delegates.

The following code example shows a method that can be used as a handler for RunWorkerCompletedEventHandler. This example is part of a larger sample for the BackgroundWorker class.

// This event handler deals with the results of the 
// background operation. 
private void backgroundWorker1_RunWorkerCompleted(
    object sender, RunWorkerCompletedEventArgs e)
{
    // First, handle the case where an exception was thrown. 
    if (e.Error != null)
    {
        MessageBox.Show(e.Error.Message);
    }
    else if (e.Cancelled)
    {
        // Next, handle the case where the user canceled  
        // the operation. 
        // Note that due to a race condition in  
        // the DoWork event handler, the Cancelled 
        // flag may not have been set, even though 
        // CancelAsync was called.
        resultLabel.Text = "Canceled";
    }
    else
    {
        // Finally, handle the case where the operation  
        // succeeded.
        resultLabel.Text = e.Result.ToString();
    }

    // Enable the UpDown control. 
    this.numericUpDown1.Enabled = true;

    // Enable the Start button.
    startAsyncButton.Enabled = true;

    // Disable the Cancel button.
    cancelAsyncButton.Enabled = false;
}

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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