上传文件

       
  public readonly IWebHostEnvironment _webHostEnvironment;

        public FileController(IWebHostEnvironment webHostEnvironment)
        {
            
            _webHostEnvironment = webHostEnvironment;
        }
 /// <summary>
        /// 上传文件
        /// </summary>
        /// <param name="files"></param>
        /// <returns></returns>
        
        public ActionResult Uploads()
        {
            List<TmpUrl> list = new List<TmpUrl>();
            var files = Request.Form.Files;
            //var a = Guid.NewGuid();
            Random random = new Random();
            var randomNumber = random.Next();
            string webRootPath = _webHostEnvironment.WebRootPath;
            var fileName = randomNumber + "-old.jpg";
            foreach (var formFile in files)
            {
                if (formFile.Length > 0)
                {
                    var filePath = Path.Combine(webRootPath + "\images", fileName);
                    using (var stream = System.IO.File.Create(filePath))
                    {
                        formFile.CopyTo(stream);
                        TmpUrl tu = new TmpUrl();
                        tu.Url = @"/images/" + fileName;
                        tu.Name = fileName;
                        list.Add(tu);

                        //生成缩略图:得到指定像素缩略图，图片较小
                        //long quality = 75;
                        //var thumbnailName = randomNumber + "-11.jpg";
                        //var thumbnailPath = Path.Combine(webRootPath + "\images" , thumbnailName);
                        //var originalImage = System.Drawing.Image
                        //    .FromStream(stream);
                        //ImagesHelper.GetSmallImage(originalImage, thumbnailPath, 230, 160, quality, "CUT");

                        //生成缩略图：生成等比例高清缩略图，图片较大
                        var thumbnailName = randomNumber + "-22.jpg";
                        var thumbnailPath = Path.Combine(webRootPath + "\images", thumbnailName);
                        var originalImage = System.Drawing.Image
                            .FromStream(stream);
                        ImagesHelper.GetThumbnailImage(originalImage, 230, 160).Save(thumbnailPath);
                    }
                }
            }
            return Json(list);
        }

        /// <summary>
        /// 图片上传本地服务器
        /// </summary>
        /// <param name="environment"></param>
        /// <returns></returns>
        [HttpPost]
        [ValidateAntiForgeryToken]
        [Obsolete]
        public async Task<IActionResult> OnPostUpload([FromServices] IHostingEnvironment environment)
        {
            List<TmpUrl> list = new List<TmpUrl>();
            var files = Request.Form.Files;
            string webRootPath = environment.WebRootPath;
            string contentRootPath = environment.ContentRootPath;
            foreach (var formFile in files)
            {
                if (formFile.Length > 0)
                {
                    var fileName = Guid.NewGuid().ToString() + "-old.jpg";
                    var path = Path.Combine(environment.WebRootPath + "\images\upload", fileName);
                    using (var fs = new FileStream(path, FileMode.CreateNew))
                    {
                        await formFile.CopyToAsync(fs);
                        TmpUrl tu = new TmpUrl();
                        tu.Url = @"/images/upload/" + fileName;
                        list.Add(tu);

                        //生成缩略图1:生成等比例高清缩略图，图片比较大
                        var thumbnailName = Guid.NewGuid().ToString() + "-11.jpg";
                        var thumbnailPath = Path.Combine(environment.WebRootPath + "\images\upload", thumbnailName);
                        var originalImage = System.Drawing.Image.FromStream(fs);
                        ImagesHelper.GetThumbnailImage(originalImage, 230, 160).Save(thumbnailPath);

                    }
                }
            }

            return new JsonResult(list);
        }