怎么把多个GridView和Repeater导入到word或者excel中

        protected void Button1_Click(object sender, EventArgs e)
        {
            StringBuilder sb = new StringBuilder();
            StringWriter sw = new StringWriter(sb);
            HtmlTextWriter htw = new HtmlTextWriter(sw);
            Page page = new Page();
            HtmlForm form = new HtmlForm();
            GridView1.EnableViewState = false;
            rptMlist.EnableViewState = false;
            myGridView.EnableViewState = false;
            page.EnableEventValidation = false;
            page.EnableViewState = false;
            // Realiza las inicializaciones de la instancia de la clase Page que requieran los diseñadores RAD.
            page.DesignerInitialize();
            page.Controls.Add(form);
            form.Controls.Add(GridView1);
            form.Controls.Add(rptMlist);
            form.Controls.Add(myGridView);
            page.RenderControl(htw);
            Response.Clear();
            Response.Buffer = true;
            Response.ContentType = "application/vnd.ms-word"; 
            Response.AddHeader("Content-Disposition", "attachment;filename=" + PID + ".doc");
            Response.Charset = "UTF-8";
            Response.ContentEncoding = Encoding.Default;
            Response.Write(sb.ToString());
            Response.End();
        }