Attempts to set focus to this element.
Assembly: PresentationCore (in PresentationCore.dll)
Even if an element is focusable and enabled, event handling within a specific tree, (such as for a composite control) might respond to the preview focus events by not allowing focus there, thus this method would return false.
If the related properties are not already true, when you call , one or more of the following events are raised in the following order: PreviewLostKeyboardFocus, PreviewGotKeyboardFocus (source is the new focus target), IsKeyboardFocusedChanged, IsKeyboardFocusWithinChanged, LostKeyboardFocus, GotKeyboardFocus (source is the new focus target).
In order for this call to be successful, some other element in the application needed to have focus previously.