สอบถามการ export to excel แบบทั้งหน้าค่ะ ช่วยหน่อยนะคะ

 protected void ImageButton1_Click(object sender, ImageClickEventArgs e)
        {

            //Response.Clear();
            //Response.Buffer = true;
            //Response.ContentType = "application/vnd.ms-excel";
            //StringWriter stringWriter = new StringWriter();

            //HtmlTextWriter htmlTextWriter = new HtmlTextWriter(stringWriter);

            //this.RenderControl(htmlTextWriter);
            //Response.Write(stringWriter.ToString());
            //Response.End();

            Response.Clear();

            Response.AddHeader("content-disposition", "attachment;filename=SubmissionCase_" + DateTime.Now.ToString("ddMMyyyy") + ".xls");

            Response.Charset = "utf-8";

            Response.Cache.SetCacheability(HttpCacheability.NoCache);

            Response.ContentType = "application/vnd.xls";

            StringWriter stringWrite = new StringWriter();

            System.Web.UI.HtmlTextWriter htmlWrite = new HtmlTextWriter(stringWrite);

          
            this.RenderControl(htmlWrite);
          

            Response.Write(stringWrite.ToString());

            Response.End();
        }