asp.net core mvc 读取文件

IFormFile, IEnumerable<IFormFile>

private IHostingEnvironment _environment;
public TestController(IOptions<MyOptions> optionsAccessor, IHostingEnvironment env)
{
_optionsAccessor = optionsAccessor;
_environment = env;
}

   
[HttpPost]
        public async Task<IActionResult> Upload(IFormFile file, bool notUsed = false)
        {
            if (file != null)
            {
                var uploads = Path.Combine(_environment.WebRootPath, "uploads");
                using (var fileStream = new FileStream(Path.Combine(uploads, file.FileName), FileMode.Create))
                {
                    await file.CopyToAsync(fileStream);
                }
            }
            return View();
        }
        [HttpPost]
        public async Task<ActionResult> Upload()
        {
            string path = Path.Combine(_environment.WebRootPath, "uploads");
            IFormFile file = Request.Form.Files["file"];
            if (file != null)
            {
                var uploads = Path.Combine(_environment.WebRootPath, "uploads");
                using (var fileStream = new FileStream(Path.Combine(uploads, file.FileName), FileMode.Create))
                {
                    await file.CopyToAsync(fileStream);
                }
            }
            return View();
        }