C# html table转excel

1.

         protected void ebtDC_Click(object sender, EventArgs e)
         {

             string elxStr = "<table><tbody><tr><td>1</td><td>11</td></tr><tr><td>2</td><td>22</td></tr></tbody></table>";
             Response.Clear();
             Response.Buffer = true;
             Response.AppendHeader("Content-Disposition", "attachment;filename=" + DateTime.Now.ToString("yyyyMMdd") + ".xls");
             Response.ContentEncoding = System.Text.Encoding.UTF8;
             Response.ContentType = "application/vnd.ms-excel";
             Response.Write(elxStr);
             Response.End();
         }

如果是身份证  string.Concat("'", dt.Rows[i]["CardNum"].ToString())