DependencyObject.RemoveHandler Method
Removes an EventHandler from an associated DependencyProperty.
Assembly: System.Workflow.ComponentModel (in System.Workflow.ComponentModel.dll)
Parameters
- dependencyEvent
- Type: System.Workflow.ComponentModel.DependencyProperty
The DependencyProperty.
- value
- Type: System.Object
The Object representing the value of this property. In this case, a Delegate type.
| Exception | Condition |
|---|---|
| ArgumentNullException | Either of the arguments is a null reference (Nothing in Visual Basic). |
| ArgumentException | The dependencyEvent is a metaproperty. |
| ArgumentException | The dependencyEvent is not an event. |
| ReadOnlyException | The value is a ActivityBind and this instance is not in DesignMode. |
Provided as a convenient direct method for removing an event delegate.
When you create a 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. Unless you remove the delegate, the event handler is called whenever the event occurs. For more information about event-handler delegates, see Events and Delegates.
Handlers are added and removed using the following code. See Send E-mail Activity Sample for more information.
#region Public Events [DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)] [Description("The SendingEmail event is raised before an email is sent through SMTP.")] [Category(EventsCategory)] [Browsable(true)] public event EventHandler SendingEmail { add { base.AddHandler(SendEmailActivity.SendingEmailEvent, value); } remove { base.RemoveHandler(SendEmailActivity.SendingEmailEvent, value); } }
- Full trust for the immediate caller. This member cannot be used by partially trusted code. For more information, see Using Libraries from Partially Trusted Code.
Windows 7, Windows Vista, Windows XP SP2, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003
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.
