I have encounter this problem on the begining of the website i created using flutter. I search every possible solution on the web, stackoverflow and other sites. Even use ChatGTP for the solution but i stuck on the same problem for several days.

After some day I find the solution what was causing it. It was IDM( Internet Download Manager). When application runs and renders an image widget which is loading from assets, my IDM application download dialog pops up and asks to download AssetManifest.bin.

Solution

I disable Chrome in IDM general setting. I work for me.

If it doesnot work then it might another problem causing it or you can try to remove/uninstal IDM to check that IDM is cause it or not.

var profileImgPath=''.obs;

changeImage(context) async{
try{
final img= await ImagePicker().pickImage(
source:ImageSource.gallery,
    imageQuality:70);
if(img=null)return;
profileImgPath.value=img.path;
}
 on PlatformException catch(e){
VxToast.show(context,msg:e.toString());
}
}

I make a function changeImage(context) which use ImagePicker package to pick a image from gallery. Here profileImgPath is used to store the value of path. I am using Getx as state management therefore I use obs. We can use this fuction as below.

ElevatedButton(
onPressed:(){
changeImage(context);
}
),

Adding Flutter projects on to firebase is one of the important things during the development process. Generally it is easy to add the flutter to the firebase but sometimes it may be time consuming and make confusion between the codes. Flutterfire CLI is a useful tools which provide commands that help ease the installation process of FlutterFire across all supported platforms.

Inside the Firebase console, go to project you want. If you haven't create a project then create a project. After you inside a project, go to to Project Overview and click on the flutter logo as shown on the image below.

When you click on that flutter logo you will be navigate to the next page that is shown below.

Follow the process i.e. login from a terminal. You can use command prompt(cmd) and run as administrator. Copy the code "firebase login" and run it. It may ask to login the the firebase again. No need to run "flutter create" because you have already create a project. If not create then create one. Click on Next.

Run the command "dart pub global activate flutterfire_cli" from any terminal. You can use command prompt(cmd). After you run the first command, now run the second command " flutterfire configure --project=Your project". Your command should match with the code given by the flutterfire. You should run the second command from the same terminal you use in the project you want to connect flutter with firebase. Now you should something like in the image below.

You have to select which platform your configuration to support. If you are using android then use space to select. After you select the platform flutterfire will automatically confirgure you settings.

At last you have to configure some code inside main.dart.

Future<void> main() async {

  WidgetsFlutterBinding.ensureInitialized(); //add this code

  // add this code  
  await Firebase.initializeApp( 
    options: DefaultFirebaseOptions.currentPlatform,
  );
  runApp(const MyApp());
}

And you are ready to go.

Here is the firebase authentication code to login and signout.

import 'package:firebase_auth/firebase_auth.dart';

class AuthController extends GetxController {
  FirebaseAuth auth = FirebaseAuth.instance;
  //textcontrollers
  var emailController = TextEditingController();
  var passwordController = TextEditingController();
  //login method
  Future<UserCredential?> loginMethod({context}) async {
    UserCredential? userCredential;
    try {
      userCredential = await auth.signInWithEmailAndPassword(
          email: emailController.text, password: passwordController.text);
    } on FirebaseAuthException catch (e) {
      VxToast.show(context, msg: e.toString());
    }
    return userCredential;
  }
  //signout method
  signoutMethod(context) async {
  try {
    await auth.signOut();
  } catch (e) {
    VxToast.show(context, msg: e.toString());
  }
}
}

For Signup

//signup method
Future<UserCredential?> signupMethod({email,password,context}) async{
UserCredential? userCredential;

try{
userCredential = 
await auth.createUserWithEmailAndPassword(email:email,password:password);
} on FirebaseAuthException catch (e){
 VxToast.show(context, msg: e.toString());
}return userCredential;
}

This cause of this error is you might not have initialized firebase before using firebase service.

How to solve this error?

To solve this error, add firebase core Flutter package in your project by adding the following lines in pubspec.yaml file:

dependencies:
  flutter:
    sdk: flutter
  firebase_core: ^2.15.0

Now in main() method of main.dart file, initialize Firebase like below before using any Firebase services:

import 'package:firebase_core/firebase_core.dart';
void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  await Firebase.initializeApp();
   //initilization of Firebase app

  // other Firebase service initialization

  runApp(MyApp());
}

Adding WidgetsFlutterBinding.ensureInitialized();
and await Firebase.initializeApp(); with async will solve the problem. Thank you

Here is the syntax of how you can remove it from the flutter application.

runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false // syntax
...

For example:

import 'package:flutter/material.dart';
void main() {
  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
        home: Scaffold(
          appBar: AppBar(
            backgroundColor: Colors.green,
            title: Center(child: Text('CodeNepal')),
      ),
          body: Text('Hello'),
    )),
  );
}

I am Rich

I deserve it

I am good,

healthy & successful

This application was placed at the price of US$999.99 and eight people buy this application from appstore.

Code for this simple application is below.

import 'package:flutter/material.dart';

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

class ImRich extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        backgroundColor: Colors.blueGrey,
        appBar: AppBar(
          backgroundColor: Colors.blueGrey[900],
          title: Center(
            child: Text(
              'I am RICH!',
              style: TextStyle(
                color: Colors.white,
                letterSpacing: 3.0,
              ),
            ),
          ),
        ),
        body: Center(
          child: Image(
            image: AssetImage('images/diamond.png'),
          ),
        ),
      ),
    );
  }
}

Here is the common the Hello word program written in flutter.

import 'package:flutter/material.dart';

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

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

@override
Widget build(BuildContext context) {
    return const MaterialApp(
    home: Center(
    child: Text('Hello World'),
        ),
    );
    }
}