private void Popup_PopupOpening(object sender, CancelEventArgs args)
 {
     var popup = sender as DesktopAlertPopup;
     SizeF dpiScale = NativeMethods.GetMonitorDpi(Screen.FromPoint(popup.Location), NativeMethods.DpiType.Effective);
     popup.Scale(dpiScale);

     Size popupSize = popup.Size;

     if (popup.LastShowDpiScaleFactor.IsEmpty)
     {
         popupSize = TelerikDpiHelper.ScaleSize(popupSize, dpiScale);
     }
     popup.Size = popupSize;
 }