Key Handler Class Won't work in Beta 2

 Since I updated to Beta 2 I cannot get this code I got off of another website to work:
public class KeyHandler
    {
        Dictionary<Key, bool> isPressed = new Dictionary<Key, bool>();
        FrameworkElement targetElement = null;
        public void ClearKeyPresses()
        {
            isPressed.Clear();
        }

        public void KeyHandlerInit(FrameworkElement target)
        {
            ClearKeyPresses();
            targetElement = target;
   &nb ...