RunWorkerCompletedEventHandler Delegate
Represents the method that will handle the RunWorkerCompleted event of a BackgroundWorker class.
Assembly: System (in System.dll)
'Declaration <HostProtectionAttribute(SecurityAction.LinkDemand, SharedState := True)> _ Public Delegate Sub RunWorkerCompletedEventHandler ( _ sender As Object, _ e As RunWorkerCompletedEventArgs _ ) 'Usage Dim instance As New RunWorkerCompletedEventHandler(AddressOf HandlerMethod)
Parameters
- sender
- Type: System.Object
The source of the event.
- e
- Type: System.ComponentModel.RunWorkerCompletedEventArgs
A RunWorkerCompletedEventArgs that contains the event data.
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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 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
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.
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