• Article

ButtonBase.OnKeyDown Method

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

Provides class handling for the KeyDown event that occurs when the user presses a key while this control has focus.

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

Syntax

'Declaration
Protected Overrides Sub OnKeyDown ( _
    e As KeyEventArgs _
)

protected override void OnKeyDown(
    KeyEventArgs e
)

Parameters

Exceptions

Exception Condition
ArgumentNullException

e is nulla null reference (Nothing in Visual Basic).

Remarks

This method marks the KeyDown event as handled by setting the KeyEventArgs.Handled property of the event data to true when ClickMode is not set to Hover and one of the following cases are true:

  • The user presses the SPACEBAR.

  • The user presses ENTER and the control accepts keyboard input.

Notes to Inheritors

If you override OnKeyDown, always call the base implementation in your OnKeyDown 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.

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.