GridView中實現表頭分層

    今天用GridView碰到一個問題，我的表頭有幾個欄位跨了兩行，有幾個欄位卻只跨了一行。問題解決辦法如下：
protected void GridView1_RowCreated(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.Header)
        {
            string strTitle = @"<tr><td rowspan = '2'>水源地名稱</td>";  //rowspan為跨行數
            strTitle = strTitle + @"<td rowspan ='2'>水源地編碼</td>";
            strTitle = strTitle + @"<td rowspan = '2'>輸水方式</td>";
            strTitle = strTitle + @"<td rowspan = '2'>是否有調蓄設施</td>";
            strTitle = strTitle + @"<td rowspan ='2'>輸水長度</td>";
            strTitle = strTitle + @"<td colspan ='6' align = 'center'>淨水廠處理工藝</td></tr>"; //colspan為跨列數
            strTitle = strTitle + @" <td>沉澱</td>";
            strTitle = strTitle + @"<td>過濾</td>";
            strTitle = strTitle + @"<td>消毒</td>";
            strTitle = strTitle + @"<td>強化深度處理</td>";
            strTitle = strTitle + @"<td>含藻水特殊處理工藝</td>";
            strTitle = strTitle + @"<td>其他</td></tr>";

            TableCellCollection tcHeader = e.Row.Cells;
            tcHeader.Clear();
            tcHeader.Add(new TableCell());
            tcHeader[0].Text = strTitle;

        }
    }