ContentElement.Focus Method ()
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.
Focus in general is governed by two separate concepts: keyboard focus and logical focus, which are not always identical. This method sets the logical focus. There is no programmatic means to set keyboard focus specifically; keyboard focus is determined by user input. For more information, see Focus Overview and Input Overview.
If the related properties are not already true, when you call PreviewLostKeyboardFocus, PreviewGotKeyboardFocus (source is the new focus target), IsKeyboardFocusedChanged, IsKeyboardFocusWithinChanged, LostKeyboardFocus, GotKeyboardFocus (source is the new focus target)., one or more of the following events are raised in the following order:
Available since 3.0