RunWorkerCompletedEventHandler Delegate
Assembly: System (in system.dll)
'Declaration Public Delegate Sub RunWorkerCompletedEventHandler ( _ sender As Object, _ e As RunWorkerCompletedEventArgs _ ) 'Usage Dim instance As New RunWorkerCompletedEventHandler(AddressOf HandlerMethod)
/** @delegate */ public delegate void RunWorkerCompletedEventHandler ( Object sender, RunWorkerCompletedEventArgs e )
Not applicable.
Parameters
- sender
The source of the event.
- e
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.
Note: |
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| The HostProtectionAttribute attribute applied to this class 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. |
The following code example shows how to use 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 Sub backgroundWorker1_RunWorkerCompleted( _ ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs) _ Handles backgroundWorker1.RunWorkerCompleted ' First, handle the case where an exception was thrown. If (e.Error IsNot Nothing) Then MessageBox.Show(e.Error.Message) ElseIf e.Cancelled Then ' 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() End If ' Enable the UpDown control. Me.numericUpDown1.Enabled = True ' Enable the Start button. startAsyncButton.Enabled = True ' Disable the Cancel button. cancelAsyncButton.Enabled = False End Sub 'backgroundWorker1_RunWorkerCompleted
// 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.get_Error() != null) {
MessageBox.Show(e.get_Error().get_Message());
}
else {
if (e.get_Cancelled()) {
// Next, handle the case where the user cancelled
// 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.set_Text("Cancelled");
}
else {
// Finally, handle the case where the operation
// succeeded.
resultLabel.set_Text(e.get_Result().ToString());
}
}
// Enable the UpDown control.
this.numericUpDown1.set_Enabled(true);
// Enable the Start button.
startAsyncButton.set_Enabled(true);
// Disable the Cancel button.
cancelAsyncButton.set_Enabled(false);
} //backgroundWorker1_RunWorkerCompleted
Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.
Note: