• Article

TreeView.OnMouseLeftButtonDown Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Provides handling for the MouseLeftButtonDown event.

Namespace:  System.Windows.Controls
Assembly:  System.Windows.Controls (in System.Windows.Controls.dll)

Syntax

'Declaration
Protected Overrides Sub OnMouseLeftButtonDown ( _
    e As MouseButtonEventArgs _
)

protected override void OnMouseLeftButtonDown(
    MouseButtonEventArgs e
)

Parameters

Remarks

The OnMouseLeftButtonDown method is called before any event handler for the MouseLeftButtonDown is called. This method allows derived classes to handle the MouseLeftButtonDown event without attaching a delegate. This is the preferred technique for handling the event in a derived class.

This implementation marks the MouseLeftButtonDown event as handled by setting the Handled property of the event data to true when the left mouse button is pressed while the mouse pointer is over a TreeViewItem associated with the TreeView control.

Notes to Inheritors

If you override OnMouseLeftButtonDown, you can prevent registered delegates from receiving events by setting Handled to true. For more information about routed events and the Handled property, see Events Overview for Silverlight.

Version Information

Silverlight

Supported in: 5, 4, 3

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.