private void ManageRoomSave_Click(object sender, RoutedEventArgs e)
 {
     try
     {
         if (ManageRoomNum.Text == "" || ManageRoomTypeCombo.SelectedIndex == -1)
         {
             MessageBox.Show("请选择一个房间或检查信息是否完整");
             return;
         }
         if (ManageRoomAddRadio.IsChecked == true)
         {
             facade.CreateRoom(ManageRoomNum.Text, (RoomType)ManageRoomTypeCombo.SelectedItem);
         }
         else if (ManageRoomChangeRadio.IsChecked == true && ManageRoomDataGrid.SelectedIndex != -1)
         {
             IRoom room = facade.GetRoom(ManageRoomID.Content.ToString());
             room.RoomNum = ManageRoomNum.Text;
             room.RType   = (RoomType)ManageRoomTypeCombo.SelectedIndex;
             facade.UpdateRoom(room);
         }
         else
         {
             MessageBox.Show("请选择一个房间或检查信息是否完整");
         }
     }
     catch (Exception ex)
     {
         MessageBox.Show("Manage Room Save Error!\n" + ex.Message);
     }
     finally
     {
         UpdateManageRoomDataGrid();
     }
 }