GridView Title上再加入一行

protected void GridView1_DataBound(object sender, EventArgs e)
    {
        GridViewRow gvr = new GridViewRow(0, 0, DataControlRowType.Header, DataControlRowState.Normal);
            TableCellCollection tcc = null;
            Table t = new Table();
            TableRow tr = new TableRow();
            TableCell tc = null;
            tc = new TableCell();
            tc.HorizontalAlign = HorizontalAlign.Center;
            tc.Text = "***";
            tc.ColumnSpan =3;
            tc.BorderWidth =1;

            gvr.Cells.Add(tc);
            GridView1.HeaderRow.Parent.Controls.AddAt(0, gvr);
    }