C#多线程下载图片 URL转Image

    public class UrlToImageConvert
    {
        int _maxTaskCount;
        /// <summary>
        /// 
        /// </summary>
        /// <param name="maxTaskCount">允许最大同时下载数量</param>
        public UrlToImageConvert(int maxTaskCount)
        {
            _maxTaskCount = maxTaskCount;
        }
        ConcurrentQueue<ImageDownTaskInfo> taskQueue = new ConcurrentQueue<ImageDownTaskInfo>();
        /// <summary>
        /// 添加下载任务
        /// </summary>
        /// <param name="url"></param>
        /// <param name="action"></param>
        public void Add(string url, Action<Image> action)
        {
            taskQueue.Enqueue(new ImageDownTaskInfo(url, action));

            if (tasks.Count <= _maxTaskCount)
            {
                tasks.Add(Task.Run(() =>
                {
                    while (taskQueue.TryDequeue(out var ti))
                    {
                        var image = DownImageFromUrl(ti.url);
                        ti.SuccessAction(image);
                    }
                }));
            }
        }

        Image DownImageFromUrl(string imageUrl)
        {
            try
            {
                WebRequest request = WebRequest.Create(imageUrl);
                HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                using (Stream stream = response.GetResponseStream())
                {
                    return Image.FromStream(stream);
                }

                //using (WebClient client = new WebClient())
                //{
                //    byte[] imageData = client.DownloadData(imageUrl);
                //    using (var stream = new System.IO.MemoryStream(imageData))
                //    {
                //        return Image.FromStream(stream);
                //    }
                //}
            }
            catch
            {
                return null;
            }

        }
        List<Task> tasks = new List<Task>();
        /// <summary>
        /// 等待任务完成
        /// </summary>
        public void WaiteAll()
        {
            Task.WaitAll(tasks.ToArray());
        }
    }

    public class ImageDownTaskInfo
    {
        public ImageDownTaskInfo(string url, Action<Image> successAction)
        {
            this.url = url;
            SuccessAction = successAction;
        }

        public string url { get; set; }
        public Action<Image> SuccessAction { get; set; }
    }