// New Reservation Tab - Availibility
        // 预订 - 查询可用房间

        /// <summary>
        /// Made by chaogeb
        /// refresh Room List
        /// </summary>
        private void updateRoomsList()
        {
            RoomType?roomType;

            if (RoomTypeCombo.SelectedIndex == -1)
            {
                roomType = null;
            }
            else
            {
                roomType = (RoomType)Enum.Parse(typeof(RoomType), RoomTypeCombo.SelectedValue.ToString());
            }

            RoomsDataGrid.ItemsSource = facade.GetAvailableRooms(roomType, StartDatePicker.SelectedDate, EndDatePicker.SelectedDate);
            //DataGridComboBoxColumn.it
        }