Nrthugu

I've got a problem with dark screen after opening minimized app (Android).

It happens in the following scenario:

I tap on a notification, the InfoPage opens. I press back button and it navigates to the main page. I minimize the app, and open it again. After opening again, the screen is black, with the name "InfoActivity" at the top, on a white bar.

Below I present the part of code for MainActivity and InfoPage.

In the MainActivity class, there is a code for opening InfoPage from notification. In the InfoPage class, there is a code for back button.

public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity

{

    Bundle bundle;



    protected override void OnCreate(Bundle bundle)

    {

        ...

    }



    protected override void OnNewIntent(Intent intent)

    {

        base.OnNewIntent(intent);

        Intent = intent;

        DisplayPage();

    }



    public void DisplayPage()

    {

        global::Xamarin.Forms.Forms.Init(this, bundle);

        Xamarin.Forms.Application app = new App();

        app.MainPage.Navigation.PushAsync(new InfoPage());

        LoadApplication(app);



    }

}





public class InfoPage : BasePage

{

    public InfoPage()

    {

        ...

    }



    private void onClickBackButton(object sender, EventArgs e)

    {

        Navigation.PopAsync();

    }



    protected override bool OnBackButtonPressed()

    {

        Navigation.PopAsync();

        return true;

    }

}



[Activity(Label = "InfoActivity")]

public class InfoActivity : Activity

{

    protected override void OnCreate(Bundle savedInstanceState)

    {

        Intent i = new Intent(this, typeof(MainActivity));

        i.AddFlags(ActivityFlags.ReorderToFront);

        this.StartActivity(i);



        base.OnCreate(savedInstanceState);

    }

}

I am going to assuming that your Activity is not defined as a "singleTop"

LaunchMode = LaunchMode.SingleTop

And thus you are trying to reinitialize the Form's application when OnNewIntent is called.

1) Set your Activity to be a singleTop:

[Activity(Label = "FormsXXXX", Icon = "@mipmap/icon", Theme = "@style/MainTheme", LaunchMode = LaunchMode.SingleTop, MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]

public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity

{

   ...

}

2) Change your DisplayPage to only include the navigation PushAsync:

public void DisplayPage()

{

    Xamarin.Forms.Application.Current.MainPage.Navigation.PushAsync(new InfoPage());

}