自一周以來我就有這個問題，我嘗試了網路中的所有內容，但仍然存在同樣的問題，這里是帶有 firebase 配置的 index.html
<script src="https://www.gstatic.com/firebasejs/8.6.1/firebase-app.js"></script>
<script>
// Import the functions you need from the SDKs you need
import { initializeApp } from "firebase/app";
// TODO: Add SDKs for Firebase products that you want to use
// https://firebase.google.com/docs/web/setup#available-libraries
// Your web app's Firebase configuration
// For Firebase JS SDK v7.20.0 and later, measurementId is optional
const firebaseConfig = {
apiKey: "jkhkhkhlkjhlkihoihhjkhkllkjhkjhk",
authDomain: "example",
projectId: "example",
storageBucket: "fdsfssfdf",
messagingSenderId: "dfdfdfdfdf",
appId: "dsfsdter54545",
measurementId: "fdfdfsdfsddf"
};
initializeApp(firebaseConfig);
</script>
<script src="main.dart.js" type="application/javascript"></script>
<!-- This script installs service_worker.js to provide PWA functionality to
application. For more information, see:
https://developers.google.com/web/fundamentals/primers/service-workers -->
<script>
var serviceWorkerVersion = null;
var scriptLoaded = false;
function loadMainDartJs() {
if (scriptLoaded) {
return;
}
scriptLoaded = true;
var scriptTag = document.createElement('script');
scriptTag.src = 'main.dart.js';
scriptTag.type = 'application/javascript';
document.body.append(scriptTag);
}
if ('serviceWorker' in navigator) {
// Service workers are supported. Use them.
window.addEventListener('load', function () {
// Wait for registration to finish before dropping the <script> tag.
// Otherwise, the browser will load the script multiple times,
// potentially different versions.
var serviceWorkerUrl = 'flutter_service_worker.js?v=' serviceWorkerVersion;
navigator.serviceWorker.register(serviceWorkerUrl)
.then((reg) => {
function waitForActivation(serviceWorker) {
serviceWorker.addEventListener('statechange', () => {
if (serviceWorker.state == 'activated') {
console.log('Installed new service worker.');
loadMainDartJs();
}
});
}
if (!reg.active && (reg.installing || reg.waiting)) {
// No active web worker and we have installed or are installing
// one for the first time. Simply wait for it to activate.
waitForActivation(reg.installing || reg.waiting);
} else if (!reg.active.scriptURL.endsWith(serviceWorkerVersion)) {
// When the app updates the serviceWorkerVersion changes, so we
// need to ask the service worker to update.
console.log('New service worker available.');
reg.update();
waitForActivation(reg.installing);
} else {
// Existing service worker is still good.
console.log('Loading app from service worker.');
loadMainDartJs();
}
});
// If service worker doesn't succeed in a reasonable amount of time,
// fallback to plaint <script> tag.
setTimeout(() => {
if (!scriptLoaded) {
console.warn(
'Failed to load app from service worker. Falling back to plain <script> tag.',
);
loadMainDartJs();
}
}, 4000);
});
} else {
// Service workers not supported. Just drop the <script> tag.
loadMainDartJs();
}
</script>
</body>
</html>
這是 main.dart 初始化 firebase
匯入'包：firebase_core/firebase_core.dart'; 匯入 'package:flutter/material.dart';
void main() {
WidgetsFlutterBinding.ensureInitialized();
runApp( MyApp());
}
class MyApp extends StatelessWidget {
MyApp({Key? key}) : super(key: key);
final Future<FirebaseApp> _initialization = Firebase.initializeApp();
// This widget is the root of your application.
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'Flutter Demo',
theme: ThemeData(
// This is the theme of your application.
//
// Try running your application with "flutter run". You'll see the
// application has a blue toolbar. Then, without quitting the app, try
// changing the primarySwatch below to Colors.green and then invoke
// "hot reload" (press "r" in the console where you ran "flutter run",
// or simply save your changes to "hot reload" in a Flutter IDE).
// Notice that the counter didn't reset back to zero; the application
// is not restarted.
primarySwatch: Colors.blue,
),
home: FutureBuilder(
future: _initialization,
builder: (BuildContext context, AsyncSnapshot<dynamic> snapshot) {
if (snapshot.hasError) {
return const Center(child: Text("error with firebase connection"),);
}
// Once complete, show your application
if (snapshot.connectionState == ConnectionState.done) {
return const MyHomePage(title: 'osama test for research');
}
// Otherwise, show something whilst waiting for initialization to complete
return const Center(child: CircularProgressIndicator(),);
},
));
}
}
class MyHomePage extends StatefulWidget {
const MyHomePage({Key? key, required this.title}) : super(key: key);
// This widget is the home page of your application. It is stateful, meaning
// that it has a State object (defined below) that contains fields that affect
// how it looks.
// This class is the configuration for the state. It holds the values (in this
// case the title) provided by the parent (in this case the App widget) and
// used by the build method of the State. Fields in a Widget subclass are
// always marked "final".
final String title;
@override
State<MyHomePage> createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
int _counter = 0;
void _incrementCounter() {
setState(() {
// This call to setState tells the Flutter framework that something has
// changed in this State, which causes it to rerun the build method below
// so that the display can reflect the updated values. If we changed
// _counter without calling setState(), then the build method would not be
// called again, and so nothing would appear to happen.
_counter ;
});
}
@override
Widget build(BuildContext context) {
// This method is rerun every time setState is called, for instance as done
// by the _incrementCounter method above.
//
// The Flutter framework has been optimized to make rerunning build methods
// fast, so that you can just rebuild anything that needs updating rather
// than having to individually change instances of widgets.
return Scaffold(
appBar: AppBar(
// Here we take the value from the MyHomePage object that was created by
// the App.build method, and use it to set our appbar title.
title: Text(widget.title),
),
body: Center(
// Center is a layout widget. It takes a single child and positions it
// in the middle of the parent.
child: Column(
// Column is also a layout widget. It takes a list of children and
// arranges them vertically. By default, it sizes itself to fit its
// children horizontally, and tries to be as tall as its parent.
//
// Invoke "debug painting" (press "p" in the console, choose the
// "Toggle Debug Paint" action from the Flutter Inspector in Android
// Studio, or the "Toggle Debug Paint" command in Visual Studio Code)
// to see the wireframe for each widget.
//
// Column has various properties to control how it sizes itself and
// how it positions its children. Here we use mainAxisAlignment to
// center the children vertically; the main axis here is the vertical
// axis because Columns are vertical (the cross axis would be
// horizontal).
mainAxisAlignment: MainAxisAlignment.center,
children: <Widget>[
const Text(
'You have pushed the button this many times:',
),
Text(
'$_counter',
style: Theme.of(context).textTheme.headline4,
),
],
),
),
floatingActionButton: FloatingActionButton(
onPressed: _incrementCounter,
tooltip: 'Increment',
child: const Icon(Icons.add),
), // This trailing comma makes auto-formatting nicer for build methods.
);
}
}
這是 pubspec.yaml
# The following adds the Cupertino Icons font to your application.
# Use with the CupertinoIcons class for iOS style icons.
cupertino_icons: ^1.0.2
firebase_core: ^1.10.0
我發現了這個問題
Running with sound null safety
Debug service listening on ws://127.0.0.1:60251/GC2a7MPp7XE=/ws
FirebaseError: Firebase: No Firebase App '[DEFAULT]' has been created - call Firebase App.initializeApp() (app/no-app).
at Object.u [as app] (https://www.gstatic.com/firebasejs/8.6.1/firebase-app.js:1:18836)
at Object.app$ [as app] (http://localhost:60182/packages/firebase_core_web/src/interop/core.dart.lib.js:31:101)
at initializeApp (http://localhost:60182/packages/firebase_core_web/firebase_core_web.dart.lib.js:104:25)
at initializeApp.next (<anonymous>)
at runBody (http://localhost:60182/dart_sdk.js:40211:34)
at Object._async [as async] (http://localhost:60182/dart_sdk.js:40242:7)
at firebase_core_web.FirebaseCoreWeb.new.initializeApp (http://localhost:60182/packages/firebase_core_web/firebase_core_web.dart.lib.js:84:20)
at initializeApp (http://localhost:60182/packages/firebase_core/firebase_core.dart.lib.js:100:59)
at initializeApp.next (<anonymous>)
at runBody (http://localhost:60182/dart_sdk.js:40211:34)
at Object._async [as async] (http://localhost:60182/dart_sdk.js:40242:7)
at Function.initializeApp (http://localhost:60182/packages/firebase_core/firebase_core.dart.lib.js:99:20)
at new main.MyApp.new (http://localhost:60182/packages/research/main.dart.lib.js:393:52)
at main$ (http://localhost:60182/packages/research/main.dart.lib.js:487:20)
at main (http://localhost:60182/web_entrypoint.dart.lib.js:36:29)
at main.next (<anonymous>)
at http://localhost:60182/dart_sdk.js:40192:33
at _RootZone.runUnary (http://localhost:60182/dart_sdk.js:40062:59)
at _FutureListener.thenAwait.handleValue (http://localhost:60182/dart_sdk.js:34983:29)
at handleValueCallback (http://localhost:60182/dart_sdk.js:35551:49)
at Function._propagateToListeners (http://localhost:60182/dart_sdk.js:35589:17)
at _Future.new.[_completeWithValue] (http://localhost:60182/dart_sdk.js:35437:23)
at http://localhost:60182/dart_sdk.js:34617:46
at _RootZone.runUnary (http://localhost:60182/dart_sdk.js:40062:59)
at _FutureListener.then.handleValue (http://localhost:60182/dart_sdk.js:34983:29)
at handleValueCallback (http://localhost:60182/dart_sdk.js:35551:49)
at Function._propagateToListeners (http://localhost:60182/dart_sdk.js:35589:17)
at _Future.new.[_completeWithValue] (http://localhost:60182/dart_sdk.js:35437:23)
at async._AsyncCallbackEntry.new.callback (http://localhost:60182/dart_sdk.js:35458:35)
at Object._microtaskLoop (http://localhost:60182/dart_sdk.js:40330:13)
at _startMicrotaskLoop (http://localhost:60182/dart_sdk.js:40336:13)
at http://localhost:60182/dart_sdk.js:35811:9
uj5u.com熱心網友回復：
請洗掉，
import { initializeApp } from "firebase/app";
并使用
// Initialize Firebase
firebase.initializeApp(firebaseConfig);
uj5u.com熱心網友回復：
將主要功能替換為，
Future main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp( MyApp());
}
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