这个combobox代码应该怎么写？
t_base_RoomTypes表里有RoomTypeID、RoomTypeCode、RoomTypeName字段我想在combobox显示RoomTypeCode，RoomTypeName值，后台value却取RoomTypeID值，
如下代码：
string tempStrSQL = "select RoomTypeID, RoomTypeCode+' '+RoomTypeName as ShowFill from t_base_RoomTypes";
DataTable tempDataTable = link.SelectDataBase(tempStrSQL);
this.roomtype.ValueMember = "tempDataTable.Rows[i][0]";
this.roomtype.DisplayMember = "ShowFill";
this.roomtype.DataSource = "tempDataTable";
问题：代码最后一行老是出现错误？？？
