Google integation in windows phone 8.1[RT] application

Question

I am working with windows phone 8.1 application and I want to login with Google Plus , for that I have create Client id and Client secret from Google

 string uri = string.Format("{0}?response_type=code&client_id={1}&redirect_uri={2}&scope={3}&approval_prompt=force",
            authEndpoint,
            clientId,
            "urn:ietf:wg:oauth:2.0:oob",
            scope);
 webBrowser.Navigate(new Uri(uri, UriKind.Absolute));

and I Got string something like 4/BGIl1Na3TQJlAD8SQ7blvHyONJ_Jyav8COHa7tIrAdo

I want User Email and Name from account for signup or login Please help me for that. Thank you

Answer 1

Implement the interafce IWebAuthenticationContinuable to your class and then under ContinueWebAuthentication() Method use this code :

var authData = GetGoogleSuccessCode(args.WebAuthenticationResult.ResponseData); 
var userData = await GetTokenAndUserInfo(authData);

private string GetGoogleSuccessCode(string data)
        {
            if (string.IsNullOrEmpty(data)) return null;
            var parts = data.Split('&')[0].Split('=');
            for (int i = 0; i < parts.Length; ++i)
            {
                if (parts[i] == "Success code")
                {
                    return parts[i + 1];
                }
            }
            return null;
        }

public async Task<string> GetTokenAndUserInfo(string code)
        {
            var client = new HttpClient();
            var auth = await client.PostAsync("https://accounts.google.com/o/oauth2/token", new FormUrlEncodedContent(new[]
                {
                    new KeyValuePair<string, string>("code", code),
                    new KeyValuePair<string, string>("client_id",Constants.GoogleAppId), 
                    new KeyValuePair<string, string>("client_secret",Constants.GoogleAppSecret), 
                    new KeyValuePair<string, string>("grant_type","authorization_code"),
                    new KeyValuePair<string, string>("redirect_uri","urn:ietf:wg:oauth:2.0:oob"),  
                }));

            var data = await auth.Content.ReadAsStringAsync();
            var j = JToken.Parse(data);
            var token = j.SelectToken("access_token");
            var searchUrl = "https://www.googleapis.com/oauth2/v2/userinfo";
            client.DefaultRequestHeaders.Add("Authorization", "Bearer " + token.ToString());
            HttpResponseMessage res = await client.GetAsync(searchUrl);
            string content = await res.Content.ReadAsStringAsync();
            return content;
        }

And add following code in App.xaml.cs file:

public static ContinuationManager ContinuationManager { get; private set; }


 public App()
{
    ContinuationManager = new ContinuationManager();
}

private void OnSuspending(object sender, SuspendingEventArgs e)
        {
            var deferral = e.SuspendingOperation.GetDeferral();
#if WINDOWS_PHONE_APP
            ContinuationManager.MarkAsStale();
#endif
            // TODO: Save application state and stop any background activity
            deferral.Complete();
        }

protected override void OnActivated(IActivatedEventArgs args)
        {
#if WINDOWS_PHONE_APP
            if (args.Kind == ActivationKind.WebAuthenticationBrokerContinuation)
            {
                var continuationEventArgs = args as IContinuationActivatedEventArgs;
                if (continuationEventArgs != null)
                {
                    ContinuationManager.Continue(continuationEventArgs);
                    ContinuationManager.MarkAsStale();
                }

            }
#endif
        }

Don't forget to include Continuation Manager class file in your project. You will get the user info.