TreeView.OnTreeNodeExpanded(TreeNodeEventArgs) Method

Definition

Namespace:

System.Web.UI.WebControls

Assembly:

System.Web.dll

Raises the TreeNodeExpanded event of the TreeView control.

C#

protected virtual void OnTreeNodeExpanded(System.Web.UI.WebControls.TreeNodeEventArgs e);

Parameters

e

TreeNodeEventArgs

A TreeNodeEventArgs that contains event data.

Remarks

The TreeNodeExpanded event is raised when a node is expanded in the TreeView control. This allows you to provide an event-handling method that performs a custom routine whenever this event occurs.

Note

If the SelectAction property for a node is set to Expand or SelectExpand, the TreeNodeExpanded event is also raised when that node is clicked in the TreeView control.

Raising an event invokes the event handler through a delegate. For more information about how to handle events, see Handling and Raising Events.

The OnTreeNodeExpanded 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 the OnTreeNodeExpanded(TreeNodeEventArgs) method in a derived class, be sure to call the OnTreeNodeExpanded(TreeNodeEventArgs) method for the base class so that registered delegates receive the event.

Applies to

See also

• TreeNodeExpanded
• SelectAction