When I press back button and reopen my app it goes back to login screen but user is still logged in

user_18929340 0
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When I press back button and reopen my app it goes back to login screen but user is still logged in. I am using navigator.pushandremoveuntill when user signs in and my app works fine until I reopen my app then I am taken back to login page which shouldn't happen as I used navigator.pushandremoveuntill and removed all the background stack screens . can any one help me .

This is my code

  signIn() async {
    if (emailController.text.isNotEmpty &&
        passwordController.text.isNotEmpty &&
        passwordController.text.length >= 6) {
      setState(() {
        isClicked = true;
      });
      await FirebaseFunctions()
          .signIn(emailController.text, passwordController.text, context);

      if (FirebaseAuth.instance.currentUser != null) {
        Navigator.pushAndRemoveUntil(
            context,
            MaterialPageRoute(builder: (context) => const HomeScreen()),
            (route) => false);
      }
    } else {
      timerSnackbar(
          backgroundColor: Colors.red,
          buttonLabel: "",
          context: context,
          contentText: "Please Check your Credentials",
          second: 2,
          afterTimeExecute: () {});
      setState(() {
        isClicked = false;
      });
    }
  }

and this is main app


void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp(
    options: DefaultFirebaseOptions.currentPlatform,
  );
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: FirebaseAuth.instance.currentUser != null
          ? const HomeScreen()
          : const SelectionScreen(),
      debugShowCheckedModeBanner: false,
    );
  }
}
flutter-navigation firebase-authentication firebase flutter android
2 Answers

The Firebase SDK automatically persists the user's credentials, and tries to restore them when the app restarts. This requires it to make a call to the server however (for example to check if the account was disabled) which takes a few moments, and during that time FirebaseAuth.instance.currentUser will be null. During that time your home: FirebaseAuth.instance.currentUser != null runs, and determines correctly that there is no user signed in yet, and renders the SelectionScreen.

The solution is to use an auth state listener, similar to what I show in this article for Android: Listen for authentication state in Android. Since this is a Stream, you can wire it up with a StreamBuilder in your widget tree, to have your UI respond to any changes in authentication state.

user_2091030

You should use SteamBuilder for this purpose. Just edit the code below depending on your need:

void main() async{
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MaterialApp(
      debugShowCheckedModeBanner: false,
      title: 'Flutter Firebase',
      theme: ThemeData(
        primarySwatch: Colors.green,
      ),
      initialRoute: "/",
      routes: {
        "/": (context) => directPage(),
      },
    ),
  );
}

class directPage extends StatelessWidget {
  const directPage({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return StreamBuilder(
        stream: FirebaseAuth.instance.authStateChanges(),
        builder: (_,snapshot){
          if(snapshot.hasData){
            return pageOne(); //your page class you want to show when you are logged in. Like showing the welcome page
          }else{
            return pageTwo(); //your page class you want to show when you are not logged in. Like showing the login page
          }
        }
    );
  }
}
user_183109490
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