protected override void OnKeyDown(KeyEventArgs e)    {        if (e.Key == Key.Enter)        {            // MoveFocus takes a TraveralReqest as its argument.            TraversalRequest request = new TraversalRequest(FocusNavigationDirection.Next);                 // Gets the element with keyboard focus.            UIElement elementWithFocus = Keyboard.FocusedElement as UIElement;                 // Change keyboard focus.            if (elementWithFocus != null)            {                elementWithFocus.MoveFocus(request);            }            e.Handled = true;        }        base.OnKeyDown(e);    }

    private void Grid_KeyDown(object sender, KeyEventArgs e)    {        var uie = e.OriginalSource as UIElement;        if (e.Key == Key.Enter)        {            uie.MoveFocus(new TraversalRequest(FocusNavigationDirection.Next));            e.Handled = true;        }    }