TreeViewItem.OnMouseLeftButtonDown(MouseButtonEventArgs) Method


Provides class handling for a MouseLeftButtonDown event.

 override void OnMouseLeftButtonDown(System::Windows::Input::MouseButtonEventArgs ^ e);
protected override void OnMouseLeftButtonDown (System.Windows.Input.MouseButtonEventArgs e);
override this.OnMouseLeftButtonDown : System.Windows.Input.MouseButtonEventArgs -> unit
Protected Overrides Sub OnMouseLeftButtonDown (e As MouseButtonEventArgs)



The event data.


If the mouse ClickCount is two, the value of the IsExpanded property switches to true or false, which causes the TreeViewItem to expand or collapse.

This implementation marks the MouseLeftButtonDown event as handled by setting the Handled property of the event data to true.

Notes to Inheritors

If you override OnMouseLeftButtonDown(MouseButtonEventArgs), always call the base implementation in your OnMouseLeftButtonDown(MouseButtonEventArgs) implementation. Failure to call the base implementation prevents base classes from handling the event with a class handler, which might change the run-time behavior of the final class. You can call the base implementation either before or after your special handling, depending on your requirements.

Applies to