Android App Crashing on Galaxy S8 Edge Only

Question

I have built the app which uses a webview in xamarin and I have tested them on many devices including the Galaxy S7 edge as I thought the reason for it not working is because of the Edge screen. However, it works fine on the S7 Edge but on the S8 Edge devices that I have tried them on, they instantly crash.

There's only two classes that I use:

MainActivity:

namespace APPNAME.Android
{
[Activity(Label = "APPNAME", Icon = "@drawable/icon", MainLauncher = 
false,
    ConfigurationChanges = ConfigChanges.ScreenSize | 
    ConfigChanges.Orientation)]

public class MainActivity : Activity
{
    WebView web_view;
    //private bool appeared;
    public class HelloWebViewClient : WebViewClient
    {
        public override bool ShouldOverrideUrlLoading(WebView view, string 
        url)
        {
            view.LoadUrl(url);
            return false;
        }
    }

    protected override void OnCreate(Bundle bundle)
    {
        Window.RequestFeature(WindowFeatures.NoTitle);
        base.OnCreate(bundle);
        // Set our view from the "main" layout resource
        SetContentView(Resource.Layout.Main);

        web_view = FindViewById<WebView>(Resource.Id.webview);
        web_view.Settings.JavaScriptEnabled = true;
        web_view.SetWebViewClient(new HelloWebViewClient());

        web_view.LoadUrl("http://link.com");
    }

    public override bool OnKeyDown(Keycode keyCode, KeyEvent e)
    {
        if (keyCode == Keycode.Back && web_view != null)
        {
            try
            {
                if (web_view.CanGoBack())
                {
                    Log.Debug("StackOverflow", "Allow browser back");
                   // Toast.MakeText(this, "Going back", 
                    ToastLength.Short).Show();
                    web_view.GoBack();
                    return true;
                }
            }
            catch (Exception ex)
            {
                Log.Error("StackOverflow", ex.Message);
            }
        }

        {
            //Log.Error("StackOv20erflow", "Null webview...");
            //StartActivity(typeof(MainActivity));
            //Finish();
            OnBackPressed();
        }
        //Log.Debug("StackOverflow", "Back button blocked");
        //Toast.MakeText(this, "Back button blocked", 
        ToastLength.Short).Show();
        return false;
    }

    public override void OnBackPressed()
    {
        Intent startMain = new Intent(Intent.ActionMain);
        startMain.AddCategory(Intent.CategoryHome);
        startMain.SetFlags(ActivityFlags.NewTask);
        StartActivity(startMain);

    }

}

}

Splash Screen:

namespace APPNAME.Android
{
[Activity(Theme = "@style/MyTheme.Splash", MainLauncher = true, NoHistory = 
true)]
public class SplashActivity : AppCompatActivity
{
    static readonly string TAG = "X:" + typeof(SplashActivity).Name;

    public override void OnCreate(Bundle savedInstanceState, 
    PersistableBundle persistentState)
    {
        base.OnCreate(savedInstanceState, persistentState);
        Log.Debug(TAG, "SplashActivity.OnCreate");
    }

    // Launches the startup task
    protected override void OnResume()
    {
        base.OnResume();
        Task startupWork = new Task(() => { SimulateStartup(); });
        startupWork.Start();
    }

    // Simulates background work that happens behind the splash screen
    async void SimulateStartup()
    {
        //Log.Debug(TAG, "Performing some startup work that takes a bit of 
        time.");
        //await Task.Delay(1000); // Simulate a bit of startup work.
        //Log.Debug(TAG, "Startup work is finished - starting 
        MainActivity.");
        //StartActivity(new Intent(Application.Context, 
        typeof(MainActivity)));
        await Task.Delay(4000);
        var intent = new Intent(this, typeof(MainActivity));
        intent.AddFlags(ActivityFlags.ClearTop | ActivityFlags.NewTask);
        StartActivity(intent);
    }
  }
}

Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
android:versionName="1.0.0.8" package="APPNAME.android" 
android:installLocation="auto" android:versionCode="8">
<uses-sdk android:minSdkVersion="14" android:targetSdkVersion="25" />
<application android:label="APPNAME" android:icon="@drawable/Icon" 
android:debuggable="false"></application>
<uses-permission android:name="android.permission.INTERNET" />
</manifest>

Not sure where to start fixing the issue as I don't know what's the cause of it.

Any help would be appreciated!

Answer 1

Avoid using async void unless in an event handler. And also NEVER create a new Task and use task.Start

Reference Async/Await - Best Practices in Asynchronous Programming

That said I would advise you create an event and handler in the SplashActivity

public class SplashActivity : AppCompatActivity {

    static readonly string TAG = "X:" + typeof(SplashActivity).Name;

    public override void OnCreate(Bundle savedInstanceState, PersistableBundle persistentState) {
        base.OnCreate(savedInstanceState, persistentState);
        Log.Debug(TAG, "SplashActivity.OnCreate");
    }

    // Launches the startup task
    private event EventHandler Starting = delegate { }
    protected override void OnResume() {
        base.OnResume();
        //subscribe to event
        Starting += Activity_Starting;
        //raise event
        Starting (this, EventArgs.Empty);
    }

    // Simulates background work that happens behind the splash screen
    async void Activity_Starting(object sender, EventArgs e) {
        //unsubscribe
        Starting -= Activity_Starting;
        //and carry on
        //Log.Debug(TAG, "Performing some startup work that takes a bit of time.");
        //await Task.Delay(1000); // Simulate a bit of startup work.
        //Log.Debug(TAG, "Startup work is finished - starting MainActivity.");
        //StartActivity(new Intent(Application.Context, typeof(MainActivity)));
        await Task.Delay(4000);
        var intent = new Intent(this, typeof(MainActivity));
        intent.AddFlags(ActivityFlags.ClearTop | ActivityFlags.NewTask);
        StartActivity(intent);
    }
  }
}