Is it possible to detect Keyboard focus events globally?

Question

The following events can be used, but, they must be attach for each element:

GotKeyboardFocus, LostKeyboardFocus

Is there a way in .NET WPF to globally detect if the focused element changed ? without having to add event listeners for all possible elements ?

Answer 1

You can do this in any class with this:

//In the constructor
EventManager.RegisterClassHandler(
        typeof(UIElement),
        Keyboard.PreviewGotKeyboardFocusEvent,
        (KeyboardFocusChangedEventHandler)OnPreviewGotKeyboardFocus);

...

private void OnPreviewGotKeyboardFocus(object sender, 
                                       KeyboardFocusChangedEventArgs e)
{

     // Your code here

}