如何合并datagrid页脚的单元格？

Question

remove some cells and set ColumnSpan property:    <asp:DataGrid id="DataGrid1" runat="server" BackColor="#C0C000" ShowFooter="true" OnItemDataBound="DataGrid1_ItemBound"></asp:DataGrid>
   ... void DataGrid1_ItemBound(object sender,  DataGridItemEventArgs e)
    {
        if (e.Item.ItemType == ListItemType.Footer)
        {
            int nCount = e.Item.Cells.Count;
            for (int i=0; i < nCount-1; i++)
                e.Item.Cells.RemoveAt(0);            e.Item.Cells[0].ColumnSpan = nCount;
        }    }