C#通过图片URL下载图片到本地磁盘

        public bool Down(string url, string dtnow)
        {
     
            bool isCompleted = false;
            
            //WebRequest wreq = WebRequest.Create(url);
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(url);
            req.Method = "GET";
            req.KeepAlive = true;
            //req.Timeout = 3000;
            req.ContentType = "image/png";
            try
            {
     
               
                HttpWebResponse wresp = (HttpWebResponse)req.GetResponse();
                Stream s = wresp.GetResponseStream();
                System.Drawing.Image img;
                img = System.Drawing.Image.FromStream(s);
                //获取程序根目录 
                if (!Directory.Exists(dtnow))
                {
     
                    Directory.CreateDirectory(dtnow);
                }

                //   图片名称
                string iname = DateTime.Now.ToString("yyMMddhhmmssfff");

                img.Save(dtnow + iname + ".jpg", ImageFormat.Jpeg);
                MemoryStream ms = new MemoryStream();
                img.Save(ms, ImageFormat.Jpeg);
                img.Dispose();
                isCompleted = true;
                return isCompleted;
            }
            catch (Exception e)
            {
     
                Debug.WriteLine(e.Message);
                return isCompleted;
            }



          

        }