There is one column in my ultra wingrid which has a valuelist bound to this column, but after I load this wingrid, the column with the valuelist is empty, it doesn't display anything, there is even no drop down arrow on this column.

The code is:

            DataSet ds = dataset with data from database ;
            BindingSource source = new BindingSource();
            source.DataSource = ds.Tables["TableNamel"];
            this.UltraWinGrid.DataSource =source;

            BindValueList();

 Now I create a new value list and add a new column to this ultra win grid, bind this new column to the newly created value list:

BindValueList()

{
            this.UltraWinGrid.DisplayLayout.ValueLists.Add("ValueList");

            this.UltraWinGrid.DisplayLayout.ValueLists["ValueList"].ValueListItems.Add("1", "1");
            this.UltraWinGrid.DisplayLayout.ValueLists["ValueList"].ValueListItems.Add("2", "2");
            this.UltraWinGrid.DisplayLayout.ValueLists["ValueList"].ValueListItems.Add("3", "3");
            this.UltraWinGrid.DisplayLayout.ValueLists["ValueList"].ValueListItems.Add("4", "4");

           this.UltraWinGrid.DisplayLayout.Bands[0].Columns.Add("NewColumn", "NewColumn");
            this.UltraWinGrid.DisplayLayout.Bands[0].Columns["NewColumn"].Style = Infragistics.Win.UltraWinGrid.ColumnStyle.DropDownList;
            this.UltraWinGrid.DisplayLayout.Bands[0].Columns["NewColumn"].ValueList = this.UltraWinGrid.DisplayLayout.ValueLists["ValueList"];

}

 But,when I run the project,after the grid is loaded, on the column of "NewColumn" there is nothing, not even the drop down arrow, the whole column is empty, I clicked on one cell of this column, there is still nothing appearts.

who knows why? is it because of the binding source of this ultra win grid?