I am still getting used to Xamarin.Forms and I am on very basic level. I went through many articles for my issue, but to the end couldn't resolve it. So...
Currently I am trying to add Google authentication inside my Xamarin.Forms application, which use Droid and iOS (no WP). So far I am following guide from here. I am using Xamarin.Auth to authenticate to Google.
Here is some part from my source code.
private async void GoogleSheetsButton_Tapped()
{
string clientId = null;
string redirectUri = null;
if (Device.RuntimePlatform == Device.iOS)
{
clientId = Constants.iOSClientId;
redirectUri = Constants.iOSRedirectUrl;
}
else if (Device.RuntimePlatform == Device.Android)
{
clientId = Constants.AndroidClientId;
redirectUri = Constants.AndroidRedirectUrl;
}
var authenticator = new OAuth2Authenticator(
clientId,
null,
Constants.Scope,
new Uri(Constants.AuthorizeUrl),
new Uri(redirectUri),
new Uri(Constants.AccessTokenUrl),
null,
true);
authenticator.Completed += OnAuthCompleted;
authenticator.Error += OnAuthError;
AuthenticationState.Authenticator = authenticator;
var presenter = new Xamarin.Auth.Presenters.OAuthLoginPresenter();
presenter.Login(authenticator);
}
The problem is coming after my method complete it's work. So after my last line:
presenter.Login(authenticator);
everything looks alright and debugging I am following that compiler goes out of method without any errors, but then I receive exception, which you can see here. It's "No compatible code running".
Here some more information regarding my source code:
- Source of "Constants" class used for client ids and URLs
public static class Constants
{
public static string AppName = "....";
// OAuth
// For Google login, configure at https://console.developers.google.com/
public static string iOSClientId = "6.....apps.googleusercontent.com";
public static string AndroidClientId = "6.....apps.googleusercontent.com";
// These values do not need changing
public static string Scope = "https://www.googleapis.com/auth/userinfo.email";
public static string AuthorizeUrl = "https://accounts.google.com/o/oauth2/auth";
public static string AccessTokenUrl = "https://www.googleapis.com/oauth2/v4/token";
public static string UserInfoUrl = "https://www.googleapis.com/oauth2/v2/userinfo";
// Set these to reversed iOS/Android client ids, with :/oauth2redirect appended
public static string iOSRedirectUrl = "com.googleusercontent.apps.6......h:/oauth2redirect";
public static string AndroidRedirectUrl = "com.googleusercontent.apps.6......l:/oauth2redirect";
}
- Source of implemented methods for on authentication complete/error, which in fact still I cannot hit because of my error
async void OnAuthCompleted(object sender, AuthenticatorCompletedEventArgs e)
{
var authenticator = sender as OAuth2Authenticator;
if (authenticator != null)
{
authenticator.Completed -= OnAuthCompleted;
authenticator.Error -= OnAuthError;
}
GoogleLoginUser user = null;
if (e.IsAuthenticated)
{
var request = new OAuth2Request("GET", new Uri(Constants.UserInfoUrl), null, e.Account);
var response = await request.GetResponseAsync();
if (response != null)
{
string userJson = await response.GetResponseTextAsync();
user = JsonConvert.DeserializeObject(userJson);
}
if (_account != null)
{
_store.Delete(_account, Constants.AppName);
}
await _store.SaveAsync(_account = e.Account, Constants.AppName);
await DisplayAlert("Email address", user.Email, "OK");
}
}
void OnAuthError(object sender, AuthenticatorErrorEventArgs e)
{
var authenticator = sender as OAuth2Authenticator;
if (authenticator != null)
{
authenticator.Completed -= OnAuthCompleted;
authenticator.Error -= OnAuthError;
}
var message = e.Message;
}
- Source of Android MainActivity where I added
public class MainActivity : FormsAppCompatActivity
{
protected override void OnCreate(Bundle bundle)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(bundle);
Forms.Init(this, bundle);
global::Xamarin.Auth.Presenters.XamarinAndroid.AuthenticationConfiguration.Init(this, bundle);
MobileBarcodeScanner.Initialize(Application);
LoadApplication(new App());
}
}
- Source of UrlSchemeInterceptorActivity
[Activity(Label = "CustomUrlSchemeInterceptorActivity", NoHistory = true, LaunchMode = LaunchMode.SingleTop)]
[IntentFilter(new[] { Intent.ActionView }, Categories = new[] { Intent.CategoryDefault, Intent.CategoryBrowsable }, DataSchemes = new[] { "com.googleusercontent.apps.6......l" }, DataPath = "/oauth2redirect")]
public class CustomUrlSchemeInterceptorActivity : Activity
{
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
var uri = new Uri(Intent.Data.ToString());
AuthenticationState.Authenticator.OnPageLoading(uri);
Finish();
}
}
Here are the main articles I went through deeply => Link 1, Link 2 and Link 3, but still couldn't resolve the issue.
I am not sure where the error comes from, or can I can I continue debugging it to resolve issue.
Thanks in advance
Solution
- Change android compiler to Android 7.0 inside Android project properties. Screenshot
- Make sure that inside Android Manifest your target is SDK Version. Screenshot
- Update all "Xamarin.Android.*" nuget packages to minimum version 25.4.0.1. Most probably they're currently to 23.3.0. I found problems with dependencies on updating it, so I make manual upload. I went and download manually each package and move it to packages folder. Then I created my own package source and give for path my folder packages and I used it to install already downloaded NuGet packages. Screenshot
- After that my issue was solved.
