how to wait until a web request with HttpWebRequest is finished?

c#, httpwebrequest, httpwebresponse, rest, windows-phone-8

Solution

Just use the newer style of asynchrony:

using (var response = (HttpWebResponse) await request.GetResponseAsync())
{
    ...
}

You shouldn't need to call `BeginXXX` much now - certainly the Microsoft APIs have pretty universally added support for the Task-based Asynchronous Pattern.

If `GetResponseAsync` isn't available, use `Task.Factory.FromAsync` just as you have for `BeginRequestStream`:

var responseTask = Task.Factory.FromAsync<WebResponse>
                                      (httpWebRequest.BeginGetResponse,
                                       httpWebRequest.EndGetResponse,
                                       null);
using (var response = (HttpWebResponse) await responseTask)
{
}

Note that because you're writing an `async` method, the initial method call will still finish quickly - but it will return a `Task<bool>` which will only complete when the async operation has completed. So you should probably be awaiting the result in the calling code, too.

Problem

I am doing a web request to login in a my web services and I have a problem. I need to wait until the login is finished before end the method that launchs the login because I need to return a boolean value that represents if the login was correct or not. In the following code I put a comment where I need wait for the result of "httpWebRequest.BeginGetResponse(...)" ``` public async Task<bool> login(string user, string passwrd) { mLoginData.setUserName(user); mLoginData.setPasswd(passwrd); string serviceURL = mBaseURL + "/pwpcloud/service/user/login"; //build the REST request // HTTP web request var httpWebRequest = (HttpWebRequest)WebRequest.Create(serviceURL); httpWebRequest.ContentType = "application/json"; httpWebRequest.Method = "POST"; // Write the request Asynchronously using (var stream = await Task.Factory.FromAsync<Stream>(httpWebRequest.BeginGetRequestStream, httpWebRequest.EndGetRequestStream, null)) { string parameters = "{\"username\":\"" + user + "\",\"password\":\"" + passwrd + "\"}"; byte[] byteArray = Encoding.UTF8.GetBytes(parameters); // Write the bytes to the stream await stream.WriteAsync(byteArray, 0, byteArray.Length); } //httpWebRequest.BeginGetResponse(new AsyncCallback(OnGettingLoginResponse), httpWebRequest); httpWebRequest.BeginGetResponse(r => { using (HttpWebResponse response = (HttpWebResponse)httpWebRequest.EndGetResponse(r)) { string data; // Read the response into a Stream object. Stream responseStream = response.GetResponseStream(); using (var reader = new StreamReader(responseStream)) { data = reader.ReadToEnd(); } responseStream.Close(); if (response.StatusCode == HttpStatusCode.OK) { dynamic jsonData = JObject.Parse(data); string token = jsonData.token; mLoginData.setToken(token); string userId = jsonData.userId; mLoginData.setUserID(userId); mLoginData.setLogged(true); //guardamos los valores en el isolatedStorageSettings para que persistan. App.settings.Clear(); App.settings.Add("userId", mLoginData.getUserID()); App.settings.Add("token", mLoginData.getToken()); App.settings.Add("userName", mLoginData.getUserName()); App.settings.Add("passwd", mLoginData.getPasswd()); App.settings.Add("logged", mLoginData.isLogged()); App.settings.Save(); } else { if (CultureInfo.CurrentUICulture.Name.ToString().Contains("ES")) { if (response.StatusCode == HttpStatusCode.Unauthorized || response.StatusCode == HttpStatusCode.BadRequest) { MessageBox.Show("Usuario o contraseña incorrectos"); } else { MessageBox.Show("Error de conexión."); } } else { if (response.StatusCode == HttpStatusCode.Unauthorized || response.StatusCode == HttpStatusCode.BadRequest) { MessageBox.Show("User or password were incorrect"); } else { MessageBox.Show("NNetwork connection error"); } } } } }, null); //here i need wait for the result of the webrequest to return true if the login was successfull. return mLoginData.isLogged(); } ``` I read a lot about this buf I didn't find the solution. Thanks everyone!!!

Original source