DoWorkEventHandler Delegate
Represents the method that will handle the DoWork event. This class cannot be inherited.
Assembly: System (in System.dll)
[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)] public delegate void DoWorkEventHandler( Object sender, DoWorkEventArgs e )
Parameters
- sender
- Type: System.Object
The source of the event.
- e
- Type: System.ComponentModel.DoWorkEventArgs
A DoWorkEventArgs that contains the event data.
When you create a DoWorkEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event-handler method is called whenever the event occurs, unless you remove the delegate. For more information about event-handler delegates, see Events and Delegates.
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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. |
The following code example demonstrates how to use the DoWorkEventHandler delegate to handle the DoWork event. For a full code listing, see How to: Run an Operation in the Background.
private void backgroundWorker1_DoWork(object sender, DoWorkEventArgs e) { // Do not access the form's BackgroundWorker reference directly. // Instead, use the reference provided by the sender parameter. BackgroundWorker bw = sender as BackgroundWorker; // Extract the argument. int arg = (int)e.Argument; // Start the time-consuming operation. e.Result = TimeConsumingOperation(bw, arg); // If the operation was canceled by the user, // set the DoWorkEventArgs.Cancel property to true. if (bw.CancellationPending) { e.Cancel = true; } }
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
