How do you integrate the new Google Sign-In on a Xamarin.Android app?

Question

I am attempting to follow Google's instructions on how to add the new Google Sign-In (not the old Google+ Sign-In) to my Xamarin.Android app. For the life of me, I cannot find the correct Google Play Services NuGet package or Xamarin component that supports the new sign-in system.

When I add the following code to the activity, I get "The type or namespace 'GoogleSignInOptions' could not be found. Are you missing an assembly reference?" build error.

// Configure sign-in to request the user's ID, email address, and basic
// profile. ID and basic profile are included in DEFAULT_SIGN_IN.
GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestEmail().build();

Here are the Xamarin.GooglePlayServices NuGet packages that are include in the project:

<package id="Xamarin.GooglePlayServices.Ads" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Analytics" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.AppIndexing" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Base" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Basement" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Identity" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Location" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Maps" version="27.0.0.0" targetFramework="MonoAndroid50" />
<package id="Xamarin.GooglePlayServices.Plus" version="27.0.0.0" targetFramework="MonoAndroid50" />

Is the new Google Sign-In system not yet supported on Xamarin or am I missing something?

Answer 1

Enable pre-release nugets and search for:

Xamarin.GooglePlayServices.Identity 29.0.0-beta1

packages.config:

<packages>
  <package id="Xamarin.Android.Support.v4" version="23.1.1.0" targetFramework="MonoAndroid44" />
  <package id="Xamarin.GooglePlayServices.Auth" version="29.0.0-beta1" targetFramework="MonoAndroid44" />
  <package id="Xamarin.GooglePlayServices.Base" version="29.0.0-beta1" targetFramework="MonoAndroid44" />
  <package id="Xamarin.GooglePlayServices.Basement" version="29.0.0-beta1" targetFramework="MonoAndroid44" />
  <package id="Xamarin.GooglePlayServices.Identity" version="29.0.0-beta1" targetFramework="MonoAndroid44" />
</packages>

C# version of Integrating Google Sign-In into Your Android App

SignInButton button = FindViewById<SignInButton> (Resource.Id.sign_in_button);
gso = new GoogleSignInOptions.Builder (GoogleSignInOptions.DefaultSignIn)
    .RequestEmail ()
    .Build ();
mGoogleApiClient = new GoogleApiClient.Builder (this)
    .EnableAutoManage(mLoginFragment, failedHandler)
    .AddApi (Auth.GOOGLE_SIGN_IN_API)
    .Build ();
button.Click += delegate {
    signIn();
};