调试WPF时如何找出哪个元素有焦点？

UIElement focusedElement = FocusManager.GetFocusedElement(this) as UIElement;
if (focusedElement != null)
{
    Console.WriteLine("Focused element: " + focusedElement.GetType().Name);
}
else
{
    Console.WriteLine("No focused element found.");
}

private void OnKeyDown(object sender, KeyEventArgs e)
{
    UIElement focusedElement = e.OriginalSource as UIElement;
    if (focusedElement != null)
    {
        Console.WriteLine("Focused element: " + focusedElement.GetType().Name);
    }
    else
    {
        Console.WriteLine("No focused element found.");
    }
}