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())