public FileResult ExportFile()

        {

            var list = GetList();

            var sbHtml = new StringBuilder();

            string title = "order";

            //标题

            sbHtml.Append("<table border='1' cellspacing='0' cellpadding='0'>");

            sbHtml.Append("<tr>");

            sbHtml.AppendFormat("<td style='font-size: 14px;text-align:center; font-weight:bold;' height='30' colspan='3'>{0}</td>", title);

            sbHtml.Append("</tr>");

            sbHtml.Append("</table>");

            sbHtml.Append("<table border='1' cellspacing='0' cellpadding='0' style='font-size: 12px;'>");

            var lstTitle = new List<string> { "Year", "Week", "Date" }; //编写表头

            sbHtml.Append("<tr>");

            foreach (var item in lstTitle)

            {

                sbHtml.AppendFormat("<td style='text-align:center;background-color: #DCE0E2; font-weight:bold;' height='25'>{0}</td>", item);

            }

            sbHtml.Append("</tr>");

            int i = ;

            var strDataType = string.Empty;

            var strQuestion = string.Empty;

            foreach (var item in list)

            {

                sbHtml.Append("</tr>");

                sbHtml.AppendFormat("<td align='center'>{0}</td><td align='center'>{1}</td><td align='center'>{2}</td>", item.Id, item.Name,item.CreateTime.ToString("yyyy-MM-dd hh:mm:ss") );

                sbHtml.Append("</tr>");

                i++;

            }

            sbHtml.Append("</table>");

            byte[] fileContents = Encoding.Default.GetBytes(sbHtml.ToString());

            string fileName = title + ".xls";

            if (Request.Browser.Browser == "IE")

            {

                Response.Charset = "GB2312";

                Response.ContentEncoding = Encoding.GetEncoding("GB2312");

                Response.AddHeader("Content-Disposition", string.Format("attachment; filename=\"{0}\"", HttpUtility.UrlEncode(fileName, Encoding.UTF8)));

            }

            return File(fileContents, "application/ms-excel", fileName);

        }