#region Excel导出
        public FileResult DataExport()
        {
            List<Phone> ExListInfo = new List<Phone>();
            Phone p = new Phone("小米5", "小米", "3500");
            Phone p1 = new Phone("小米2A", "小米", "2500");
            Phone p2 = new Phone("荣耀20Pro", "华为", "3500");
            ExListInfo.Add(p);
            ExListInfo.Add(p1);
            ExListInfo.Add(p2);

            //ExportExcel(ExListInfo);

            //创建Excel文件的对象
            NPOI.HSSF.UserModel.HSSFWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
            //添加一个sheet
            ISheet sheet1 = book.CreateSheet("Sheet1");

            //貌似这里可以设置各种样式字体颜色背景等，但是不是很方便，这里就不设置了

            //给sheet1添加第一行的头部标题
            IRow row1 = sheet1.CreateRow(0);
            row1.CreateCell(0).SetCellValue("手机名称");
            row1.CreateCell(1).SetCellValue("手机型号");
            row1.CreateCell(2).SetCellValue("手机价格");
            //....N行

            //将数据逐步写入sheet1各个行
            for (int i = 0; i < ExListInfo.Count; i++)
            {
                IRow rowtemp = sheet1.CreateRow(i + 1);
                rowtemp.CreateCell(0).SetCellValue(ExListInfo[i].PhoneName);
                rowtemp.CreateCell(1).SetCellValue(ExListInfo[i].PhoneType);
                rowtemp.CreateCell(2).SetCellValue(ExListInfo[i].PhonePrice);
                //....N行
            }
            // 写入到客户端 
            MemoryStream ms = new MemoryStream();
            book.Write(ms);
            ms.Seek(0, SeekOrigin.Begin);
            DateTime dt = DateTime.Now;
            string dateTime = dt.ToString("yyMMddHHmmssfff");
            string fileName = "手清价格一览表" + dateTime + ".xls";

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



        }

        #endregion