Flutter: Issue with showing home page if the user already logged in else show the login page

I am trying to show the home page if the user already logged in else I need to show the login page.

I have tried like below:

void main() async{
  bool isLoggedIn = false;
  SharedPreferences prefs = await SharedPreferences.getInstance();
  bool isLoggedInValueAvailable = prefs.containsKey('isLoggedIn');
  if(isLoggedInValueAvailable)
  {
    isLoggedIn = prefs.getBool('isLoggedIn')?? false;
  }
 else
  {
    isLoggedIn = false;
  }
  runApp(MyApp(isLoggedIn: isLoggedIn));
}

class MyApp extends StatelessWidget {
  final bool isLoggedIn;
  MyApp({required this.isLoggedIn});

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: isLoggedIn ? const Home() : const LoginDemo(),
      debugShowCheckedModeBanner: false,
      routes: {
        '/home': (context) => Home(),
        '/sign_up': (context) => SignUp(),
      },
    );
  }
}

But when I run this a white screen is only showing, not redirecting to login or home page. No exception or errors are showing the console.

>Solution :

void main() async {
  WidgetsFlutterBinding.ensureInitialized(); // <== add this line
  ...
}