问题返回Filecontent，contentType，fileName;当我尝试导出时

如何解决问题返回Filecontent，contentType，fileName;当我尝试导出时

我正在尝试使用asp.net MVC中的apiController导出Excel文件 这是我的代码：

[HttpPost]
[HttpRoute("report/historicalExpirations/excel")]
public Microsoft.AspNetCore.Mvc.IActionResult Excel([FromBody] HistoricalExpirationDto HeDto) {
  string contentType = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet";
  string fileName = "VencimientosHistoricos.xlsx";
  var res = _reportRepository.HistoricalExpirations(HeDto.CompanyCode,HeDto.Date,HeDto.EntityCode);

  using(var workbook = new XLWorkbook()) {
    var worksheet = workbook.Worksheets.Add("Historico de Vencimientos");
    var currentRow = 1;

    #region Headers
    worksheet.Cell(currentRow,1).Value = "Fecha";
    worksheet.Cell(currentRow,2).Value = "Id";
    worksheet.Cell(currentRow,3).Value = "Sector";
    worksheet.Cell(currentRow,4).Value = "Proveedor";
    worksheet.Cell(currentRow,5).Value = "Cuit Proveedor";
    worksheet.Cell(currentRow,6).Value = "Proveedor Habilitado";
    worksheet.Cell(currentRow,7).Value = "Codigo Recurso";
    worksheet.Cell(currentRow,8).Value = "Tipo Recurso";
    worksheet.Cell(currentRow,9).Value = "Recurso";
    worksheet.Cell(currentRow,10).Value = "Recurso Habilitado";
    worksheet.Cell(currentRow,11).Value = "Motivo";

    #endregion

    #region Body
    foreach(var reg in res) {
      currentRow++;
      worksheet.Cell(currentRow,1).Value = reg.Date;
      worksheet.Cell(currentRow,2).Value = reg.Id;
      worksheet.Cell(currentRow,3).Value = reg.Sector;
      worksheet.Cell(currentRow,4).Value = reg.Provider;
      worksheet.Cell(currentRow,5).Value = reg.CuitProvider;
      worksheet.Cell(currentRow,6).Value = reg.EnabledProvider;
      worksheet.Cell(currentRow,7).Value = reg.ResourceCode;
      worksheet.Cell(currentRow,8).Value = reg.ResourceType;
      worksheet.Cell(currentRow,9).Value = reg.Resource;
      worksheet.Cell(currentRow,10).Value = reg.EnabledResource;
      worksheet.Cell(currentRow,11).Value = reg.Motive;
    }
    #endregion

    using(var stream = new MemoryStream()) {
      workbook.SaveAs(stream);
      var content = stream.ToArray();
      return File(content,contentType,fileName);
    }
  }
}

错误： GravedadCódigoDescripciónProyecto ArchivoLíneaEstado suprimido 错误CS1955没有使用通用文件名“文件”，无法调用。