跨越代理取得uri数据的方法[C#]

            HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(http://hq.sinajs.cn/list=sh000001);
            WebProxy myProxy = new WebProxy();
            myProxy.Address = new Uri("http://proxy:port");
            myProxy.Credentials = new NetworkCredential("username", "password");
            request.Proxy = myProxy;

            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream respStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(respStream);
            string line = reader.ReadLine();