This implementation marks the KeyDown event as handled by setting the 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 AcceptsReturn is true for this control.
In all other cases, this implementation does not change the handled state (the Handled property) of the KeyDown event data.
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.
Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)