private void btnGiamGiaNhom_Click(object sender, RoutedEventArgs e)
 {
     if (ucGiamGiaNhom == null)
     {
         ucGiamGiaNhom = new UserControlLibrary.UCGiamGiaNhom();
     }
     spNoiDung.Children.Clear();
     ucGiamGiaNhom.Height = spNoiDung.ActualHeight;
     ucGiamGiaNhom.Width  = spNoiDung.ActualWidth;
     spNoiDung.Children.Add(ucGiamGiaNhom);
 }
 private void btnGiamGiaNhom_Click(object sender, RoutedEventArgs e)
 {
     if (ucGiamGiaNhom==null)
     {
         ucGiamGiaNhom = new UserControlLibrary.UCGiamGiaNhom();
     }
     spNoiDung.Children.Clear();
     ucGiamGiaNhom.Height = spNoiDung.ActualHeight;
     ucGiamGiaNhom.Width = spNoiDung.ActualWidth;
     spNoiDung.Children.Add(ucGiamGiaNhom);
 }