다음을 통해 공유


TextBox.OnMouseLeftButtonDown Method

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

Called before MouseLeftButtonDown event occurs.

Namespace:  System.Windows.Controls
Assembly:  System.Windows (in System.Windows.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 event 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.

TextBox handles cursor placement and selection in MouseLeftButtonDown event. Derived classes can prevent the TextBox from processing the TextBox event by setting the Handled property of the event data to true.

Notes to Inheritors

When overriding OnMouseLeftButtonDown method in a derived class, be sure to call the base class’s OnMouseLeftButtonDown method so that registered delegates receive the event.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

Platforms

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