Raises the BeforeExpand event.
[Visual Basic] Overridable Protected Sub OnBeforeExpand( _ ByVal e As TreeViewCancelEventArgs _ ) [C#] protected virtual void OnBeforeExpand( TreeViewCancelEventArgs e ); [C++] protected: virtual void OnBeforeExpand( TreeViewCancelEventArgs* e );
Raising an event invokes the event handler through a delegate. For more information, see Raising an Event.
The OnBeforeExpand method also allows derived classes to handle the event without attaching a delegate. This is the preferred technique for handling the event in a derived class.
Notes to Inheritors: When overriding OnBeforeExpand in a derived class, be sure to call the base class's OnBeforeExpand method so that registered delegates receive the event.
Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows .NET Server family
TreeView Class | TreeView Members | Wimark.Controls Namespace