Webapi导出数据到Execl中

1 安装EPPlus.core

2创建一个帮助类

public class ExcelHelper
    {
        /// <summary>
        /// 导出数据到execl
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="dataList">数据</param>
        /// <param name="headers">表头</param>
        /// <returns></returns>
        public static MemoryStreamDto CreateDataToExcel<T>(List<T> dataList, List<string> headers)
        {
            string fileName = $"{Guid.NewGuid().ToString()}.xlsx";
            //保存在内存里，小文件，大文件的话得另外想办法  
            var stream = new MemoryStream();
            using (ExcelPackage package = new ExcelPackage(stream))
            {
                ExcelWorksheet worksheet = package.Workbook.Worksheets.Add("sheet1");
                worksheet.Cells.LoadFromCollection(dataList, true);
                for (int i = 0; i < headers.Count; i++)
                {
                    worksheet.Cells[1, i + 1].Value = headers[i];
                }
                package.Save();
            }
            stream.Position = 0;
            var memoryStreamDto = new MemoryStreamDto()   //一个自定的Dto，需要传什么参数可以自行定义
            {
                Stream = stream,
                FileName = fileName
            };
            return memoryStreamDto; 
        }
    }

服务器调用

            var dataList = EntityList;    //要导入到Execl中的数据
            var headers = new List<string>() { "表头列名1", "表头列名2", "表头列名3", "表头列名4", "表头列名5" };
            var memoryStreamDto = ExcelHelper.CreateExcelFromList(dataList, headers);

控制器调用

　　　　public async Task<IActionResult> ExportDataListToExecl()   //与方法JsonResult不同，这里返回的是IActionResult
        {var result =  _service.ExportDataListToExecl();   //服务器的方法
            return File(result.Stream, "application/octet-stream", result.FileName);   //返回文件流形式，调用这个接口时，直接下载execl
        }