Return a File From ApplicationService Base Class - asp.net-core

Question

I'm trying to export data in SQL table called UploadedFileEntities into excel file I use angular in front-end and .NET core in Backend (ASP.Net Core boilerplate framework).
the problem is I can't return a file by Application class because of File is a class for Controller Base class,
So how could I return File from ApplicationService Base class?
Here is my code
using Abp.Application.Services;
using Abp.Application.Services.Dto;
using Abp.Domain.Repositories;
using Abp.Domain.Uow;
using Abp.EntityFrameworkCore;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using OfficeOpenXml;
using PHC.Entities;
using PHC.EntityFrameworkCore;
using PHC.MySystemServices.MyApplicationServices.DTO;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using IdentityModel.Client;
using Ninject.Activation;
using DocumentFormat.OpenXml.ExtendedProperties;
namespace PHC.MySystemServices.MyApplicationServices
{
public class MyApplicationAppService : AsyncCrudAppService<MyApplication, MyApplicationDto, int, PagedAndSortedResultRequestDto, MyApplicationDto>
{
private readonly IDbContextProvider<PHCDbContext> _dbContextProvider;
private PHCDbContext db => _dbContextProvider.GetDbContext();
private readonly IRepository<MyApplication,int> _repository;
private IHostingEnvironment _env;
public MyApplicationAppService(IDbContextProvider<PHCDbContext> dbContextProvider, IRepository<MyApplication, int> repository, IHostingEnvironment hostingEnvironment) :base(repository)
{
_repository = repository;
_dbContextProvider = dbContextProvider;
this._env = hostingEnvironment;
}
public async Task<IActionResult> ExportV2(CancellationToken cancellationToken)
{
// query data from database
await Task.Yield();
var list = db.UploadedFileEntities.ToList();
var stream = new MemoryStream();
ExcelPackage.LicenseContext = LicenseContext.NonCommercial; // this is important
using (var package = new ExcelPackage(stream))
{
var workSheet = package.Workbook.Worksheets.Add("Sheet1");
workSheet.Cells.LoadFromCollection(list, true);
package.Save();
}
stream.Position = 0;
string excelName = $"UserList-{DateTime.Now.ToString("yyyyMMddHHmmssfff")}.xlsx";
//return File(stream, "application/octet-stream", excelName);
return new File(stream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet", excelName); //it doesn't work
}
}
if I return File Visual studio show me
non-invocable member 'File' cannot be used like a method
if I return new File Visual studio show me:
Cannot create an instance of the static class 'File'

Answer 1

The file method is derived from ControllerBase.File while you do not inherit it.
You could try FileStreamResult like
return new FileStreamResult(stream, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet")
{
FileDownloadName = excelName
};