GoogleWebAuthorizationBroker 在 Xamarin Android 上不起作用

我想在我的移动应用程序中使用 google oauth 授权。我之前已经在测试控制台应用程序中实现了这个功能。但是在我在 Xamarin Android 中重新构建代码后出现了问题。代码 ：

private void _youtubeOAuth() 
{
    string[] scopes =
        {
        "https://www.googleapis.com/auth/youtube.readonly",
    };
    var clientSecrets = new ClientSecrets
    {
        ClientId = "00000v.apps.googleusercontent.com",
        ClientSecret = "GOCS****Jo8EMYq"
    };

    UserCredential credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
        clientSecrets,
        scopes,
        "user_id",
        CancellationToken.None,
        new FileDataStore(""))
    .Result;

    var youtubeService = new YouTubeService(
        new BaseClientService.Initializer()
        {
            HttpClientInitializer = credential,
            ApplicationName = "Desktop client 1"
        });

    var channelsListRequest = youtubeService.Channels.List("contentDetails, snippet");
    channelsListRequest.Mine = true;
    ChannelListResponse channelsListResponse = channelsListRequest.Execute();
    string chanellTitle = channelsListResponse.Items[0].Snippet.Title;
    Console.WriteLine(chanellTitle + " Subscriptions:");
}

这是脏代码，但在控制台应用程序中执行良好。当我尝试在 Xamarin 中启动方法时，我捕获了异常：

无法使用“https://accounts.google.com/o/oauth2/v2/auth?access_type=offline&response_type=code&client_id=****.apps.googleusercontent.com&redirect_uri=http%3A%2F%2F127.0.0”启动浏览器.1%3A40031%2Fauthorize%2F&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fyoutube.readonly" 用于授权。

我不确定移动应用程序权限中的问题，因为这段代码执行得很好。

private async void _openBrowser() 
{
    Uri uri = new Uri("https://accounts.google.com/o/oauth2/v2/auth?access_type=offline&response_type=code&client_id=****.apps.googleusercontent.com&redirect_uri=http%3A%2F%2F127.0.0.1%3A40031%2Fauthorize%2F&scope=https%3A%2F%2Fwww.googleapis.com%2Fauth%2Fyoutube.readonly");
    await Browser.OpenAsync(uri, BrowserLaunchMode.SystemPreferred);
}