public static void ExportExcel(string FileName, StringBuilder table)
        {
            HttpContext.Current.Response.ClearContent();
            HttpContext.Current.Response.ContentEncoding = System.Text.Encoding.GetEncoding("GB2312");//设置输出流的字符集
            HttpContext.Current.Response.Charset = "gb2312";
            HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + HttpUtility.UrlEncode(FileName));

            HttpContext.Current.Response.ContentType = "application/vnd.ms-excel";
            StringWriter sw = new StringWriter(table);
            //HtmlTextWriter htw = new HtmlTextWriter(sw);

            //Page page = new Page();
            //page.EnableEventValidation = false;
            //page.DesignerInitialize();
            //page.RenderControl(htw);
            HttpContext.Current.Response.Write("<meta http-equiv=\"content-type\" content=\"application/ms-excel; charset=gb2312\"/>" + sw.ToString());
            HttpContext.Current.Response.Flush();
            HttpContext.Current.Response.End();
        }