后台列表导出Excel

小白做的导出功能

js部分：

 function btn_export() {
        dialogConfirm("注：您确定要导出报表吗？", function (r) {
            if (r) {
                Loading(true, "正在导出..."); 
                window.setTimeout(function () {
                    $.ajax({
                        url: "",
                        type: "post",
                        data: {
                           start_date:$("#start_date").val(),
                           end_date:$("#end_date").val()
                        },
                        dataType: "json",
                        success: function (result) {
                            if (result.code != 200) {
                                dialogMsg(result.msg, 0);
                                Loading(false);
                                return;
                            }
                            Loading(false);
                            dialogMsg(result.msg, 1);
                            window.location = result.path;
                        }
                    });
                }, 1000);
            }
        });
      
    }

 控制器部分：

 public ActionResult ExportExcel(string start_date,string end_date)
        {
            string path = "";
            string result= excelexport.ExcelExport(start_date, end_date,ref path);
            object obj = new
            {
                code = 200,
                path = path,
                msg = "导出成功"
            };
            if (result!= "")
            {
                obj = new
                {
                    code = 400,
                    msg = result,
                };
            }
            return Json(obj, JsonRequestBehavior.AllowGet);
        }

　　BLL部分：  引入using System.IO和using NPOI.XSSF.UserModel，在解决方案下添加一个空文件夹derivation 和一个带有标题栏的excel文件的stencil文件夹，excel文件里的标题要跟代码循环部分数据对齐

 public string ExcelExport(string start_date, string end_date,ref string path)
        {
            var bus = new
            {           
                all = true,
                start_date,
                end_date
            };
            var res = dbFactory.GetData(0, out dynamic out_dynamic, bus);
            if (res != "") return "无数据";
            try
            {
                string templetFileName = HttpContext.Current.Server.MapPath("~\\stencil\\数据报表.xlsx");
                string name = DateTime.Now.ToString("yyyy-MM-dd") + "数据报表.xlsx";
                path = "/derivation/" + name;

                string reportFileName = HttpContext.Current.Server.MapPath("~\\derivation\\" + name);
                FileStream file = new FileStream(templetFileName, FileMode.Open, FileAccess.Read);
                XSSFWorkbook hssfworkbook = new XSSFWorkbook(file);
                var sheet = hssfworkbook.GetSheet("Sheet1");

                var list = out_dynamic.list;
                int index = 0;

                foreach (var item in list)
                {
                    index = list.IndexOf(item) + 1;
                    sheet.CreateRow(index).CreateCell(0);
                    var row = sheet.GetRow(index);
                    row.GetCell(0).SetCellValue(item.id.ToString());
                    row.CreateCell(2);
                    row.GetCell(2).SetCellValue(item.name.ToString());
                    row.CreateCell(3);
                    row.GetCell(3).SetCellValue(item.value.ToString());
                    row.CreateCell(4);
                    row.GetCell(4).SetCellValue(item.price.ToString());
                    row.CreateCell(5);
                    row.GetCell(5).SetCellValue(item.start_addr_name.ToString());
                    row.CreateCell(6);
                    row.GetCell(6).SetCellValue(item.end_addr_name.ToString());
                    row.CreateCell(8);
                    row.GetCell(8).SetCellValue(item.create_date.ToString());
                }
                index++;
                sheet.CreateRow(index).CreateCell(0);
                sheet.GetRow(index).GetCell(0).SetCellValue("总计:" + list.Count + "条");

                using (FileStream filess = File.OpenWrite(reportFileName))
                {
                    hssfworkbook.Write(filess);
                }

                file.Close();
                return "";
            }
            catch (Exception ex)
            {
                return ex.Message;
            }
        }