function PostAndGetFileByUrl(url,type,postdata) {        var temp;        $.ajax({            url: url,            type: type,            data: {keyword:postdata},            async: true,            dataType: "Text",            success: function (data) {                downloadFile(data);            }        });        return temp;    }    function btn_export()    {        var $gridList = $("#gridList");        var rowData = http://www.mamicode.com/$gridList.jqGrid(‘getGridParam‘,‘selarrrow‘);"/RunManage/EnvData/WriteToExcel", "POST", rowData.join(","));    }<a id="NF-export" class="btn btn-primary" onclick="btn_export()"><i class="fa fa-plus"></i>导出XLS</a>

[HttpPost]        [HandlerAjaxOnly]        public ActionResult WriteToExcel(string keyword)        {            DataTable dt = new DataTable();            dt.Columns.Add("AAAA");            dt.Columns.Add("BBBB");            List<ItemEntity> dataList = EnvDataApp.GetListByKeywordArray(keyword);//请写自己的获取List方法            foreach (var item in dataList)            {                DataRow dr = dt.NewRow();                dr["AAAA"] = item.F_ID;                dr["BBBB"] = item.F_FullName;                dt.Rows.Add(dr);            }            NPOIExcel npoiexel = new NPOIExcel();            string fileDir = DateTime.Now.ToString("yyyyMMdd");            string fileName = "G" + Guid.NewGuid().ToString("N") + ".xls";            string destDir = Server.MapPath(@"/XlsTemp") + "\\" + fileDir + "\\";            if (!Directory.Exists(destDir))            {                Directory.CreateDirectory(destDir);            }            npoiexel.ToExcel(dt, "数据", "Sheet1", destDir + fileName);            return Content("/XlsTemp/" + fileDir + "/" + fileName);        }    }