//焦点消失
 private void txtUc_LostFocus(object sender, RoutedEventArgs e)   //todo:仍不完美,焦点移除该控件后不能使之消失
 {
     if (dgUc.CaptureMouse() || dpUc.CaptureMouse())
     {
         return;
     }
     dgUc.Visibility = Visibility.Collapsed;
     dpUc.Visibility = Visibility.Collapsed;
 }