【NPOI】WebAPI-使用NPOI导出Excel

1.安装nuget包

2.封装方法

　　　　 public byte[] ExportToByteArray(IEnumerable<string> headerText,
                                        IEnumerable<string[]> dataList,
                                        string extraMessage = null)
        {
            IWorkbook workbook = Write(headerText, dataList, extraMessage);
            var memoryStream = new MemoryStream();
            workbook.Write(memoryStream);

            return memoryStream.ToArray();
        }

        private static IWorkbook Write(IEnumerable<string> headerText,
                                       IEnumerable<string[]> dataList,
                                       string extraMessage = null)
        {
            IWorkbook wb = new XSSFWorkbook();
            ISheet sheet = wb.CreateSheet("Sheet1");
            var rowIndex = ;

            if (!string.IsNullOrEmpty(extraMessage))
            {
                SetExcelRowForExtraMessage(sheet, extraMessage);
                rowIndex += ;
            }

            SetExcelHeaderRow(sheet, rowIndex, headerText.ToList());
            rowIndex += ;

            if (!dataList.Any())
            {
                return wb;
            }

            for (var i = ; i < dataList.Count(); i++)
            {
                SetExcelBodyRow(sheet, rowIndex + i, dataList.ElementAt(i));
            }

            //优化表格的列宽
            int maxColumnIndex = dataList.Max(row => row.Count());
            for (var i = ; i < maxColumnIndex; i++)
            {
                sheet.AutoSizeColumn(i);
            }

            return wb;
        }

3.Controller调用方法

  　　　 /// <summary>
        /// 基金净值下载
        /// </summary>
        [HttpGet]
        public HttpResponseMessage DownloadExecl()
        {
            try
            {
                //获取数据         var productList = _productService.GetProductList();

                var exportData = ProductList.Select(t => new {
                    t.Date,
                    t.Name
                }).ToList();
                //下载文件
                var fileName = $"{DateTime.Today:yyyyMMdd}.xlsx";
                var bytes = _exportor.ExportToByteArray(HeaderText, exportData, "");
                var response = GetFileResponse(fileName, bytes);

                return response;
            }
            catch (Exception)
            {
               return new HttpResponseMessage(System.Net.HttpStatusCode.NoContent);
            }
        }

        private HttpResponseMessage GetFileResponse(string fileName, byte[] bytes)
        {
            HttpResponseMessage response = new HttpResponseMessage(System.Net.HttpStatusCode.OK);
            var mime = System.Web.MimeMapping.GetMimeMapping(fileName);
            var stream = new MemoryStream(bytes);
            response.Content = new StreamContent(stream);
            response.Content = new StreamContent(stream);
            bool isFirefox = Request.Headers.UserAgent.ToString()
                                .IndexOf("Firefox", StringComparison.CurrentCultureIgnoreCase) > -;
            response.Content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(mime);
            response.Content.Headers.ContentDisposition =
                    new ContentDispositionHeaderValue("attachment")
                    {
                            FileName = isFirefox ? fileName :
                            HttpUtility.UrlEncode(fileName, System.Text.Encoding.UTF8)
                    };
            response.Content.Headers.ContentLength = stream.Length;

            return response;
        }

　　　　 /// <summary>
        /// Excel列头
        /// </summary>
        private static readonly string[] HeaderText =
        {
            "时间",
            "名称"
        };