TreeView.OnBeforeCollapse(TreeViewCancelEventArgs) Method

Reference

Definition

Namespace:: System.Windows.Forms

Assembly:: System.Windows.Forms.dll

Source:: TreeView.cs

Source:: TreeView.cs

Source:: TreeView.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Raises the BeforeCollapse event.

protected:
 virtual void OnBeforeCollapse(System::Windows::Forms::TreeViewCancelEventArgs ^ e);

protected public:
 virtual void OnBeforeCollapse(System::Windows::Forms::TreeViewCancelEventArgs ^ e);

protected virtual void OnBeforeCollapse (System.Windows.Forms.TreeViewCancelEventArgs e);

protected internal virtual void OnBeforeCollapse (System.Windows.Forms.TreeViewCancelEventArgs e);

abstract member OnBeforeCollapse : System.Windows.Forms.TreeViewCancelEventArgs -> unit
override this.OnBeforeCollapse : System.Windows.Forms.TreeViewCancelEventArgs -> unit

Protected Overridable Sub OnBeforeCollapse (e As TreeViewCancelEventArgs)

Protected Friend Overridable Sub OnBeforeCollapse (e As TreeViewCancelEventArgs)

Parameters

e: TreeViewCancelEventArgs

A TreeViewCancelEventArgs that contains the event data.

Remarks

Raising an event invokes the event handler through a delegate. For more information, see Handling and Raising Events.

The OnBeforeCollapse 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 OnBeforeCollapse(TreeViewCancelEventArgs) in a derived class, be sure to call the base class's OnBeforeCollapse(TreeViewCancelEventArgs) method so that registered delegates receive the event.

Applies to

Κοινή χρήση μέσω