string pathUrl = "";

            Stream s = null;
            System.Net.HttpWebRequest request = null;
            System.Net.HttpWebResponse response = null;
            request = (System.Net.HttpWebRequest)System.Net.WebRequest.Create(pathUrl);
            request.Timeout = 5000; // 超時時間
            response = (System.Net.HttpWebResponse)request.GetResponse();
            string path = "/Image/";
            string pathname = path + DateTime.Now.ToString("yyyyMMddHHss") + ".png";
            s = response.GetResponseStream();
            var imgs = Image.FromStream(s);
            imgs.Save(pathname);
            s.Close();
            return pathname;