通过Src下载图片存到指定目录

           string src = temppartsrc + "." + pictype;
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(src);
            request.AllowAutoRedirect = true;

            WebProxy proxy = new WebProxy();
            proxy.BypassProxyOnLocal = true;
            proxy.UseDefaultCredentials = true;
            request.Proxy = proxy;
            WebResponse response = request.GetResponse();
            string virthpath = "";
            using (Stream stream = response.GetResponseStream())
            {
                using (MemoryStream ms = new MemoryStream())
                {
                    Byte[] buffer = new Byte[1024];
                    int current = 0;
                    while ((current = stream.Read(buffer, 0, buffer.Length)) != 0)
                    {
                        ms.Write(buffer, 0, current);
                    }
                    byte[] arry = ms.ToArray();
                     virthpath = "./image/" + DateTime.Now.ToString("yyyyMMddhhmmss") + "." + pictype;
                    string path = Server.MapPath(virthpath);
                    File.WriteAllBytes(path, arry);
                }
            }