Saving data in windows phone received from WCF/web service .

Question

Saving data in windows phone received from WCF/web service . The response may be received after sometime so how to handle this situation. Saving data is no problem but How to handel if data is received late

Answer 1

You can use this code (show the code from my project):

public void sendPost(string postData, Action<MyResponse, Exception> callback, CreateResponse creater)
        {
            HttpWebRequest webRequest = (HttpWebRequest)WebRequest.Create(UrlRequest);
            webRequest.Method = "POST";
            webRequest.ContentType = "application/x-www-form-urlencoded";
            webRequest.Accept = "application/json";
            webRequest.AllowAutoRedirect = true;
            webRequest.BeginGetRequestStream(new AsyncCallback(getRequestStreamCallback), new Request()
            {
                HttpRequest = webRequest,
                PostData = postData,
                Url = UrlRequest,
                CallBack = callback,
                Creater = creater
            });
        }

 private void getRequestStreamCallback(IAsyncResult asynchronousResult)
        {
            var request = (Request)asynchronousResult.AsyncState;
            // End the stream request operation
            Stream postStream = request.HttpRequest.EndGetRequestStream(asynchronousResult);

            byte[] byteArray = Encoding.UTF8.GetBytes(request.PostData);

            // Add the post data to the web request
            postStream.Write(byteArray, 0, byteArray.Length);
            postStream.Close();

            // Start the web request
            request.HttpRequest.BeginGetResponse(new AsyncCallback(getResponseCallback), request);
        }

private void getResponseCallback(IAsyncResult asynchronousResult)
        {
            var request = (Request)asynchronousResult.AsyncState;
            try
            {

                HttpWebResponse response;

                // End the get response operation
                response = (HttpWebResponse)request.HttpRequest.EndGetResponse(asynchronousResult);
                Stream streamResponse = response.GetResponseStream();
                StreamReader streamReader = new StreamReader(streamResponse);
                var myResponse = streamReader.ReadToEnd();
                streamResponse.Close();
                streamReader.Close();
                response.Close();
                MyResponse response_obj = request.Creater.CreateResponseObj();
                using (MemoryStream stream = new MemoryStream(Encoding.Unicode.GetBytes(myResponse)))
                {
                    DataContractJsonSerializer serializer = new DataContractJsonSerializer(response_obj.GetType());
                    response_obj = (GYResponse)serializer.ReadObject(stream);
                    if (request.CallBack != null)
                    {
                        request.CallBack.Invoke(response_obj, null);
                    }
                }
            }
            catch (WebException e)
            {

                if (request.CallBack != null)
                {
                    request.CallBack.Invoke(null, e);
                }
            }
        }
public void getInfo(string uid, Action<MyResponse, Exception> callback)
        {
            CreateResponse creater = new CreateResponseGetInfo();
            string model = "User";
            string method = "getInfo";
            Params parametrs = new Params();
            parametrs.Uid = uid;
            //create yor request
            string request = getRequestString(model, method, parametrs, Atoken);                 
            sendPost(request, callback, creater);
        }

So, you call method, which send request to web service postRequester.getInfo(uid, ResponseHandler) and use delegate for processing result.

private void ResponseHandler(MyResponse result, Exception error)
        {
            if (error != null)
            {
                string err = error.Message;
                return;
            }
            else
            {
                var infoResponse = result as ResponseGetInfo;
                if (infoResponse != null)
                {
                      //result processing..              
                }

            }
        }

Answer 2

All the web requests you make in a Windows Phone app are Asynchronous. That means, you make a web request from your app and attach a handler to handle the response when it comes. In the response handler, you will have to take care of the response and do whatever you want with it.

Check this link Using WebClient and HttpWebRequest