mvc 根据模板导出excel，直接导出文件流

1.c#

/// <summary>
        /// 导出员工
        /// </summary>
        /// <returns></returns>
        [HttpGet]
        public FileResult ExportEmployee()
        {
            var eid = getEnterpriseId();

            LogWriter.ToDebug($"导出员工开始");

            string templateUrl = "/ExportFile/Template/ExportEmployeesTemplate.xls";
            //string temporaryUrl = $"/ExportFile/Temporary/ExportEmployees_{DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss")}.xls";

            string templateRealUrl = Request.MapPath(templateUrl);
            //string temporaryRealUrl = Request.MapPath(temporaryUrl);

            //System.IO.File.Copy(templateRealUrl, temporaryRealUrl, true);
            var result = ExportEmployees(eid, templateRealUrl);


            LogWriter.ToDebug($"导出员工结束");
            return result; //return Json(new ResultInfo(1001, "导出员工失败"));

        }

private FileResult ExportEmployees(Guid eId, string tempFileUrl)
        {
            var employeesList = EnterpriseBLL.GetExportEmployees(eId);
            IWorkbook workbook;
            try
            {
                using (FileStream stream = System.IO.File.Open(tempFileUrl, FileMode.Open, FileAccess.Read))
                {
                    workbook = new HSSFWorkbook(stream);
                    ISheet sheet = workbook.GetSheet("Sheet1");
                    for (int i = 0; i < employeesList.Count; i++)
                    {
                        IRow row = sheet.CreateRow(i + 3);
                        for (int j = 0; j < 7; j++)
                        {
                            ICell cell = row.CreateCell(j);
                            cell.SetCellValue(EnterpriseBLL.getCellValue(employeesList[i], j));
                        }
                    }

                }
                //转为字节数组  
                NpoiMemoryStream streamOut = new NpoiMemoryStream();
                streamOut.AllowClose = false;
                workbook.Write(streamOut);
                streamOut.Seek(0, SeekOrigin.Begin);
                //return File(stream, "application/vnd.ms-excel", file);
                return File(streamOut, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", "Employees.xls");

            }
            catch (Exception ex)
            {
                LogWriter.ToError($"ZJCX.ZJCDPC.WebUI->EnterpriseBLL->ExportEmployees内部错误，{ex.Message}", ex);
                throw ex;
            }
        }
        //新建类 重写Npoi流方法
        public class NpoiMemoryStream : MemoryStream
        {
            public NpoiMemoryStream()
            {
                AllowClose = true;
            }

            public bool AllowClose { get; set; }

            public override void Close()
            {
                if (AllowClose)
                    base.Close();
            }
        }

前端：

通过创建a标签实现重命名文件

this.$getDownload('/API/ExportEmployee').then(res => {
                    let blob = new Blob([res.data], { type: "application/vnd.openxmlformats-officedocument.spreadsheethml.sheet" });
                    let objctUrl = URL.createObjectURL(blob);

                    var a = document.createElement('a');
                    a.innerHTML = "员工信息.xls";
                    a.download = "员工信息.xls";
                    a.href = objctUrl;
                    document.body.appendChild(a);

                    var evt = document.createEvent("MouseEvents");
                    evt.initEvent("click", false, false);
                    a.dispatchEvent(evt);
                    document.body.removeChild(a);
                })

前端用的vue-anxio，需要注意：

//get请求封装
export function getDownload(url) {
    return new Promise((resolve, reject) => {

        axios({
            method: 'get',
            url: baseUrl+url,
            responseType: 'arraybuffer'
        }).then(res => {
            resolve(res)
            }, err => {
                console.log('get 报错');
                reject(err);
            })
    })
};