Xamarin.Auth OAuth Google API，用于Android的用户身份验证

Question

我一直在尝试通过Google OAuth 2.0进行身份验证。关注this链接。已经能够打开Google Auth页面并成功登录。问题是登录后我被重定向到谷歌搜索页面。如果我关闭应用程序然后在OAuth2Authenticator的OnAuthCompleted方法中，我将e.IsAuthenticated设置为false并且无法获取用户的任何信息。

Xamarin共享库代码：

var authenticator = new OAuth2Authenticator(
                                "somekey-somekey1.apps.googleusercontent.com",
                                null,
                                "email",
                                new Uri("https://accounts.google.com/o/oauth2/v2/auth"),
                                new Uri("com.companyname.somenameofapp:/oauth2redirect"),
                                new Uri("https://www.googleapis.com/oauth2/v4/"),
                                null,
                                true);
        var presenter = new Xamarin.Auth.Presenters.OAuthLoginPresenter();
        presenter.Login(authenticator);
        authenticator.Completed += OnAuthCompleted;
        AuthenticationState.Authenticator = authenticator;

AuthenticationState类

public class AuthenticationState

    public static OAuth2Authenticator Authenticator;

OnAuthCompleted方法

private async void OnAuthCompleted(object sender, AuthenticatorCompletedEventArgs e)

    if (e.IsAuthenticated)
    
        await Navigation.PushAsync(new GoogleLoginSuccess());

主要活动代码

protected override void OnCreate(Bundle savedInstanceState)

    TabLayoutResource = Resource.Layout.Tabbar;
    ToolbarResource = Resource.Layout.Toolbar;
    base.OnCreate(savedInstanceState);
    global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
    global::Xamarin.Auth.Presenters.Xamarinandroid.AuthenticationConfiguration.Init(this, savedInstanceState);
    LoadApplication(new App());

CustomUrlSchemeInterceptorActivity

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;

namespace XamAppGoogleAuth.Droid

    [Activity(Label = "CustomUrlSchemeInterceptorActivity")]
    [IntentFilter(
        new[]  Intent.ActionView ,
        Categories = new[]  Intent.CategoryDefault, Intent.CategoryBrowsable ,
        DataSchemes = new[]  "com.companyname.somenameofapp" ,
        DataPath = ":/oauth2redirect",
        DataHost = "com.companyname.somenameofapp")]
    public class CustomUrlSchemeInterceptorActivity : Activity
    
        protected override void OnCreate(Bundle savedInstanceState)
        
            base.OnCreate(savedInstanceState);
            global::Android.Net.Uri uri_android = Intent.Data;

            Uri uri_netfx = new Uri(uri_android.ToString());

            // load redirect_url Page
            AuthenticationState.Authenticator.OnPageLoading(uri_netfx);

            var intent = new Intent(this, typeof(MainActivity));
            intent.SetFlags(ActivityFlags.ClearTop | ActivityFlags.SingleTop);
            StartActivity(intent);

            this.Finish();

            return;

AndroidManifest

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.companyname.somenameofapp">
  <uses-sdk android:minSdkVersion="21" android:targetSdkVersion="27" />
  <application android:label="somenameofapp.Android"></application>
  <activity android:name="somenameofapp.Android.MainActivity" android:label="MainActivity">
    <intent-filter>
      <action android:name="android.intent.action.VIEW" />
      <category android:name="android.intent.category.DEFAULT" />
      <category android:name="android.intent.category.BROWSABLE" />
      <data android:scheme="com.companyname.somenameofapp" android:host="com.companyname.somenameofapp" />
    </intent-filter>
  </activity>
</manifest>

当我明确关闭自定义选项卡时，我会使用以下Toast消息导航回应用程序。

我想要的是在用户使用Google OAuth进行身份验证后，他们会被重定向回应用程序，我可以根据需要获取访问令牌和其他信息。我已经有很多关于此的链接，但还没有找到解决方案。请帮助