Screen keeps rendering after initializing Firebase-CodePudding

So I'm trying to implement authentication using Firebase and I got an error saying

[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

I found a way to deal with the error by adding the following code to my main.dart file:

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(StockApp());
}

The method to check if the user is logged in is as follows:

isLoggedIn() async {
    _auth.authStateChanges().listen((user) {
      if (user != null)
        Navigator.push(
            context, MaterialPageRoute(builder: (context) => Home()));
      else
        Navigator.push(
            context, MaterialPageRoute(builder: (context) => Login()));
    });
  }

@override
  void initState() {
    super.initState();
    this.isLoggedIn();
  }

The error is gone but now my login page keeps rendering endlessly.

CodePudding user response：

Here you are navigating to the screen on listening the stream so it will continuously pushing the widget to the stack.Instead of this you can use

User? _user;
isLoggedIn() async {
    _auth.authStateChanges().listen((user) {
      _user=user;
      setState((){})
      
    });

    if (user != null)
        Navigator.push(
            context, MaterialPageRoute(builder: (context) => Home()));
      else
        Navigator.push(
            context, MaterialPageRoute(builder: (context) => Login()));
  }

CodePudding user response：

Wrap this.isLoggedIn method inside addPostFrameCallback as

WidgetsBinding.instance.addPostFrameCallback((_){
     this.isLoggedIn()
});