void gv_CustomRowCellEditForEditing(object sender, CustomRowCellEditEventArgs e)
        {
            xCol xc;

            if (ListCols.TryGetValue(e.Column.AbsoluteIndex, out xc))
            {
                ((BindingSource)xc.rle.DataSource).DataMember = string.Empty;
                ((BindingSource)xc.rle.DataSource).DataSource =
                    xc.GetSrcHandler(eColl.GetParent());
            }
        }