windows phone 7 通过Post提交URL到服务器,从服务器获取数据(比如登陆时候使用)

HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(UrlManager.Login());
            myRequest.Method = "POST";
            myRequest.ContentType = "application/x-www-form-urlencoded";

            myRequest.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), myRequest);



private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
        {
            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
            System.IO.Stream postStream = request.EndGetRequestStream(asynchronousResult);

            // Prepare Parameters String
            string parametersString = "username=用户名&password=密码";
            //foreach (KeyValuePair<string, string> parameter in parameters)
            //{
            //    parametersString = parametersString + (parametersString != "" ? "&" : "") + string.Format("{0}={1}", parameter.Key, parameter.Value);
            //}

         

            byte[] byteArray = System.Text.Encoding.UTF8.GetBytes(parametersString);
            // Write to the request stream.
            postStream.Write(byteArray, 0, parametersString.Length);
            postStream.Close();
            // Start the asynchronous operation to get the response
            request.BeginGetResponse(new AsyncCallback(GetResponseCallback), request);
        }



 private void GetResponseCallback(IAsyncResult asynchronousResult)
        {
            HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
            HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(asynchronousResult);
            Stream streamResponse = response.GetResponseStream();
            StreamReader streamRead = new StreamReader(streamResponse);
            string responseString = streamRead.ReadToEnd();
            // Close the stream object
            streamResponse.Close();
            streamRead.Close();
       }