MemoryStream StreamToMemoryStream(Stream instream)

        {

            MemoryStream outstream = new MemoryStream();

            const int bufferLen = ;

            byte[] buffer = new byte[bufferLen];

            int count = ;

            while ((count = instream.Read(buffer, , bufferLen)) > )

            {

                outstream.Write(buffer, , count);

            }

            return outstream;

        }

                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url + (data == "" ? "" : "?" + data));

                request.Method = "GET";

                using (HttpWebResponse response = request.GetResponse() as HttpWebResponse)

                {

                    if (response.StatusCode == HttpStatusCode.OK)

                    {

                        Stream rs =response.GetResponseStream();                                  

                        var ms = StreamToMemoryStream(rs);

                        ms.Seek(, SeekOrigin.Begin);                        int buffsize =(int)ms.Length; //rs.Length 此流不支持查找,先转为MemoryStream

                        byte[] bytes = new byte[buffsize];

                        ms.Read(bytes, , buffsize);

                        ms.Flush();ms.Close();
　　　　　　　　　　　　　　rs.Flush();rs.Close();
                }