public void OnKeyCancel(object sender, KeyCancelEventArguments args)
        {
            if (Page == null)
            {
                return;
            }

            KeyDownEventArguments prevArgs;

            if (!_pressedKeys.TryGetValue(args.Key, out prevArgs))
            {
                return;
            }

            _pressedKeys.Remove(args.Key);
            Page.OnKeyCancel(sender, args);
        }
 public virtual void OnKeyCancel(object sender, KeyCancelEventArguments args)
 {
 }