把GridView中的数据导入excel中，遇到有关问题

把GridView中的数据导入excel中，遇到问题
 #region
        protected void GridViewToExcel(GridView Gdv, string stitle)
        {
            try
            {
                Response.Clear();
                Response.Buffer = true;
                Response.Charset = "GB2312";
                string filename = "attachment;filename=" + System.Web.HttpUtility.UrlEncode(stitle, System.Text.Encoding.UTF8) + ".xls";
                Response.AppendHeader("Content-Disposition", filename);
                   Response.ContentEncoding = System.Text.Encoding.UTF7;
                Response.ContentType = "application/ms-excel";
                System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
                System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
                Gdv.AllowPaging = false;
                Gdv.DataBind();
                Gdv.RenderControl(oHtmlTextWriter);
                Response.Output.Write(oStringWriter.ToString());
                Response.Flush();
                Response.End(); 
            }
            catch (Exception ex)
            {
                lblMessage.Text = ex.Message;
            }
        }
        #endregion
运行过程中会有报错（由于代码已经过优化或者本机框架位于调用堆栈之上,无法计算表达式的值），问题应该出在  Response.End()上，但是不用  Response.End()改用HttpContext.Current.ApplicationInstance.CompleteRequest 方法，报错是没有了，但是下载下来的excel不能打开。求高手解决，在上面代码的基础上如何修改！
[解决办法]
亲，试试加上这个吧：

        
public override void VerifyRenderingInServerForm(Control control)
 {
  //no code need
 }

            public void ExportExcel()
           {
            string dateTime = DateTime.Now.ToString("yyyy/MM/dd hh:mm:ss");
            Response.Clear();
            Response.Buffer = true;
            Response.Charset = "UTF-8";
            Response.AppendHeader("Content-disposition", "attachment;filename=" + dateTime + ".xls");
            Response.ContentEncoding = Encoding.GetEncoding("UTF-8");
            Response.ContentType = "EXECL";
            StringWriter sWriter = new StringWriter();
            HtmlTextWriter hWriter = new HtmlTextWriter(sWriter);
            this.rpt.RenderControl(hWriter);//rpt是存放数据table的标签的id,必须是runat="server"。
            Response.Write(sWriter);
            Response.End();
}