c# mvc使用 npoi下载 excel

 IWorkbook book = new NPOI.HSSF.UserModel.HSSFWorkbook();
 //添加一个sheet
 ISheet sheet1 = book.CreateSheet("Sheet1");

 //给sheet1添加第一行的头部标题
 NPOI.SS.UserModel.IRow row1 = sheet1.CreateRow();
 row1.CreateCell().SetCellValue("编号");
 row1.CreateCell().SetCellValue("姓名");

 MemoryStream ms = new MemoryStream();
 book.Write(ms);
 ms.Seek(, SeekOrigin.Begin);
 return File(ms, "application/vnd.ms-execel", "1.xls");