Was this page helpful?
Your feedback about this content is important. Let us know what you think.
Additional feedback?
1500 characters remaining
RunWorkerCompletedEventHandler Delegate
Collapse the table of content
Expand the table of content

RunWorkerCompletedEventHandler Delegate

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

Namespace:  System.ComponentModel
Assemblies:   System.ComponentModel.EventBasedAsync (in System.ComponentModel.EventBasedAsync.dll)
  System (in System.dll)

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.

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;
}

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8
Show:
© 2015 Microsoft