使用 Magicodes.IE.Excel包
　　　　　官网地址:https://docs.xin-lai.com/2020/02/12/%E7%BB%84%E4%BB%B6/Magicodes.IE/Magicodes.IE%202.0%E5%8F%91%E5%B8%83/
        /// <summary>
        /// 导出数据
        /// </summary>
        /// <returns></returns>
        public async Task<string> HSCodeExcel(HSCodeExcel excel)
        {string sql = "SELECT * FROM HSCode WHERE [Id] IN (" + excel.Id + ")";var da = await QuerySql<config_archives_HSCodeExcel>(sql);
            if (da.Count == 0)
            {
                throw new SjzyException("查询出现异常", ResponseEnum.NotAcceptable);
            }
            string date = "_" + DateTime.Now.ToString("yyyyMMddhhmmss");
            var filePath = Path.Combine(Path.GetFullPath("../Excel"), excel.ExcelName + date + ".xlsx");
            IExporter exporter = new ExcelExporter();
            var result = await exporter.Export(filePath, da);
            return result.FileName;
        }
　　　　　使用 DotNetCore.NPOI包
        /// <summary>
        /// 导入数据
        /// </summary>
        /// <param name="formCollection"></param>
        /// <returns></returns>
        public async Task<bool> HSCodeExcels(IFormFile formCollection,int UserId)
        {
            var file = formCollection.FileName;  //文件名称
            string filePhysicalPath = Path.GetFullPath("../Excels/");  //文件存储文件夹
            if (!Directory.Exists(filePhysicalPath)) //判断上传文件夹是否存在，若不存在，则创建
            {
                Directory.CreateDirectory(filePhysicalPath); //创建文件夹
            }
            string date = DateTime.Now.ToString("yyyyMMddhhmmss")+ "_";
            string path = filePhysicalPath + date + file;
            using (FileStream fs = System.IO.File.Create(path))
            {
                formCollection.CopyTo(fs);
                fs.Flush();
            }
            IWorkbook workbook = null;  //新建IWorkbook对象
            FileStream fileStream = new FileStream(path, FileMode.Open, FileAccess.Read);
            if (path.IndexOf(".xlsx") > 0) // 2007版本
            {
                workbook = new XSSFWorkbook(fileStream);  //xlsx数据读入workbook
            }
            else if (path.IndexOf(".xls") > 0) // 2003版本
            {
                workbook = new HSSFWorkbook(fileStream);  //xls数据读入workbook
            }
            ISheet sheet = workbook.GetSheetAt(0);  //获取第一个工作表
            IRow row;//新建当前工作表行数据
            List<config_archives_HSCode> config_Archives = new List<config_archives_HSCode>();
            for (int i = 0; i < sheet.LastRowNum; i++)  //对工作表每一行
            {
                row = sheet.GetRow(i+1);   //row读入第i行数据
                if (row != null)
                {
                    config_archives_HSCode HSCode = new config_archives_HSCode();
                    HSCode.HSCode = row.GetCell(0).ToString();
                    HSCode.CName = row.GetCell(1).ToString();
                    HSCode.EName = row.GetCell(2).ToString();
                    HSCode.CreationTime = DateTime.Now;
                    config_Archives.Add(HSCode);
                }
            }
            fileStream.Close();
            workbook.Close();
            var da = await Add(config_Archives);
            return da > 0;
        }