private void Export(string FileType, string FileName)
        {
            Response.Charset = "GB2312";
            Response.ContentEncoding = System.Text.Encoding.UTF7;
            Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName, Encoding.UTF8).ToString());
            Response.ContentType = FileType;
            this.EnableViewState = false;
            StringWriter tw = new StringWriter();
            HtmlTextWriter hw = new HtmlTextWriter(tw);
            datagrid1.RenderControl(hw);
            Response.Write(tw.ToString());
            Response.End();
        }
        public override void VerifyRenderingInServerForm(Control control)
        {
        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            Export("application/ms-excel", "结果.xls");

        }