没有创建 Firebase App - 调用 Firebase.initializeApp()

Question

I am trying to run my app and it is giving the following error

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

I have already called firebase.initializeApp() but still the error is same. here is my code of main file

    void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return ChangeNotifierProvider(
      create: (_) => AppointmentsProvider(),
      child: MaterialApp(
        title: 'Car Wash App',
        theme: ThemeData(
          primarySwatch: Colors.blue,
          visualDensity: VisualDensity.adaptivePlatformDensity,
         
        ),
        home: FutureBuilder(
          future: Firebase.initializeApp(),
          builder: (ctx, snap) =>
              snap.connectionState == ConnectionState.waiting
                  ? Center(
                      child: Text('Loading...'),
                    )
                  : StreamBuilder(
                      stream: FirebaseAuth.instance.authStateChanges(),
                      builder: (ctx, snapShot) =>
                          snapShot.hasData ? HomePage() : UserAuth(),
                    ),
        ),
        routes: {
          HomePage.routeName: (_) => HomePage(),
          HistoryPage.routeName: (_) => HistoryPage(),
          MyAppointments.routeName: (_) => MyAppointments(),
          PackagesPage.routeName: (_) => PackagesPage(),
          VehicleType.routeName: (_) => VehicleType(),
          SlotPage.routeName: (_) => SlotPage(),
          ExtraServicesPage.routeName: (_) => ExtraServicesPage(),
          SummaryPage.routeName: (_) => SummaryPage(),
          DetailedScreen.routeName: (_) => DetailedScreen(),
          PaymentMethodScreen.routeName: (_) => PaymentMethodScreen(),
        },
      ),
    );
  }
}

Any kind of help is much appreciated. Thank you

Answer 1

You should initialise it in main().

For example:

import 'package:firebase_core/firebase_core.dart';
import 'firebase_options.dart';

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

This link might be helpful for you.

Answer 2

If the above answers don't help, you can solve the problem by following steps:

delete the project and take backup of lib folder and pubspec.yaml file.
Create a new project with the same name
copy backed up files to the newly created project.
run flutter pub get
you are good to go

It literally solved my problem. I hope this will help.

Answer 3

Firebase.initializeApp() is an asynchronous function. You should use "await" to ensure Firebase initialization. And use WidgetsFlutterBinding.ensureInitialized() to prevent flutter errors.

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

Answer 4

The problem is that you have configure firebase in your flutter project but you have not initialized it before the app starts.

You need to initialize the firebase sdk asynchronously. This is how to go about it.

 Future<void> main() async { WidgetsFlutterBinding.ensureInitialized(); await Firebase.initializeApp(); runApp(const MyApp()); }

Answer 5

This error is know to occur when you fail to add the required dependencies in both your android side of things in project and app level build.gradle files

Answer 6

1. Check your android/build.gradle file. Inside dependecies add

   classpath 'com.google.gms:google-services:4.3.14' (use latest version)

2. Go to app/build.gradle file. Add the plugin outside dependencies

   apply plugin: 'com.google.gms.google-services'