多个上传

        public ActionResult Index(IEnumerable<HttpPostedFileBase> files)
        {
            foreach (var file in files)
            {
                if (file.ContentLength > 0)
                {
                    var fileName = Path.GetFileName(file.FileName);
                    var path = Path.Combine(Server.MapPath("~/App_Data/uploads"), fileName);
                    file.SaveAs(path);
                }
            }
            return RedirectToAction("Index");
        }