未创建Firebase应用程序“[DEFAULT]”—在Flutter和Firebase中调用Firebase. initializeapp ()

我正在构建一个Flutter应用程序，我已经集成了Firebase，但当我点击一个按钮注册，登录或注销时，我一直得到这个错误。我看到其他人也问过同样的问题，但似乎没有一个对我有用。我正在使用Flutter和Android Studio。我该如何解决这个问题?

这是我的代码的摘录

class HomeScreen extends StatefulWidget {
  @override
  _HomeScreenState createState() => _HomeScreenState();
}

class _HomeScreenState extends State<HomeScreen> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.red,
      body: Center(
        child: Container(
          child: RaisedButton(
            onPressed: () {
              FirebaseAuth.instance.signOut().then((value) {
                Navigator.pushReplacement(
                    context,
                    MaterialPageRoute(
                        builder: (context) =>
                            LoginScreen()));
              });
            },
            child: Text("Logout"),
          )
        )
      )
    );
  }
}

下面是抛出的异常

══╡ EXCEPTION CAUGHT BY GESTURE ╞═══════════════════════════════════════════════════════════════════
The following FirebaseException was thrown while handling a gesture:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

When the exception was thrown, this was the stack:

#0      MethodChannelFirebase.app (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:118:5)
#1      Firebase.app (package:firebase_core/src/firebase.dart:52:41)
#2      FirebaseAuth.instance (package:firebase_auth/src/firebase_auth.dart:37:47)
#3      _HomeScreenState.build.<anonymous closure> (package:cosytok/screens/home.dart:20:28)
#4      _InkResponseState._handleTap (package:flutter/src/material/ink_well.dart:992:19)
#5      _InkResponseState.build.<anonymous closure> (package:flutter/src/material/ink_well.dart:1098:38)
#6      GestureRecognizer.invokeCallback (package:flutter/src/gestures/recognizer.dart:184:24)
#7      TapGestureRecognizer.handleTapUp (package:flutter/src/gestures/tap.dart:524:11)
#8      BaseTapGestureRecognizer._checkUp (package:flutter/src/gestures/tap.dart:284:5)
#9      BaseTapGestureRecognizer.handlePrimaryPointer (package:flutter/src/gestures/tap.dart:219:7)
#10     PrimaryPointerGestureRecognizer.handleEvent (package:flutter/src/gestures/recognizer.dart:477:9)
#11     PointerRouter._dispatch (package:flutter/src/gestures/pointer_router.dart:78:12)
#12     PointerRouter._dispatchEventToRoutes.<anonymous closure> (package:flutter/src/gestures/pointer_router.dart:124:9)
#13     _LinkedHashMapMixin.forEach (dart:collection-patch/compact_hash.dart:377:8)
#14     PointerRouter._dispatchEventToRoutes (package:flutter/src/gestures/pointer_router.dart:122:18)
#15     PointerRouter.route (package:flutter/src/gestures/pointer_router.dart:108:7)
#16     GestureBinding.handleEvent (package:flutter/src/gestures/binding.dart:220:19)
#17     GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:200:22)
#18     GestureBinding._handlePointerEvent (package:flutter/src/gestures/binding.dart:158:7)
#19     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:104:7)
#20     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:88:7)
#24     _invoke1 (dart:ui/hooks.dart:267:10)
#25     _dispatchPointerDataPacket (dart:ui/hooks.dart:176:5)
(elided 3 frames from dart:async)

Handler: "onTap"
Recognizer:
  TapGestureRecognizer#f0104
════════════════════════════════════════════════════════════════════════════════════════════════════

════════ Exception caught by gesture ═══════════════════════════════════════════════════════════════
The following FirebaseException was thrown while handling a gesture:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()

当前回答

如果你正确设置了Firebase，不要忘记添加

等待

之前

Firebase.initializeApp ();

这就是异常的主要问题。

等待Firebase.initializeApp ();

2022-01-21 04:11:23

其他回答

自2017年8月以来，所有Firebase服务都已更新，因此在使用任何Firebase产品之前，您必须在主程序中调用Firebase. initializeapp()，例如:

如果您希望在flutter应用程序中使用firebase_core插件，则在您的pubspec中。Yaml文件添加firebase_core如下所示

dependencies:
  flutter:
    sdk: flutter
  firebase_core: ^1.19.1

然后调用Firebase.initializeApp():在你的应用中。如下所示:

import 'package:firebase_core/firebase_core.dart';

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

2021-06-02 08:12:11

我需要用FlutterFire cli重新配置Firebase应用程序。

https://firebase.flutter.dev/docs/cli

通过NPM Install -g firebase-tools安装firebase-tool 安装flutterfire cli: dart pub global activate flutterfire_cli 运行此命令在项目中配置firebase: flutterfire configure

按上述链接进行初始化，如下所示:

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

当它等待调用时，应用程序将显示启动屏幕，Firebase可能无法初始化，因此我接下来用另一个FutureBuilder作为主屏幕，以确保在使用FirebaseAuth之前，Firebase应用程序已初始化。

home: FutureBuilder(
          future: Firebase.initializeApp(),
          builder: (context, snapshot) {
            if (snapshot.hasError) {
              return Text(snapshot.error.toString(),
                  style: TextStyle(fontSize: 10));
            }

            if (snapshot.connectionState == ConnectionState.done) {
              return StreamBuilder(
                stream: FirebaseAuth.instance.authStateChanges(),
                builder: (context, snapshot) {
                  return snapshot.hasData ? Home() : AuthPage();
                },
              );
            } else {
              return Text('');
            }
          })

2022-03-09 08:51:25

这是2022年初始化firebase的方法

首先，使用此链接==>安装FlutterFire 颤振消防安装环节

安装FlutterFire之后，需要在lib/main中添加这些代码行。飞镖文件

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

然后编辑你的主函数如下所示

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

这在将来可能会改变，因此请参考下面的最新实现参考

初始化FlutterFire #

2022-02-22 10:46:14

试试下面的代码。它将同时解决IOS和Android的问题。

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

    void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  if (Platform.isIOS) {
    await Firebase.initializeApp(
      options: const FirebaseOptions(
          apiKey: "found in your google service-info.plist",
          appId: "found in your google service-info.plist",
          messagingSenderId: "found in firebase",
          projectId: "found in firebase"),
    );
  } else {
    await Firebase.initializeApp();
  }
  runApp(const MyApp());
}

2022-11-08 07:18:52

彼得的答案是完美的!但如果您的代码中仍然出现错误，并遵循Flutter Firebase代码实验室，请注意，这些教程截至2020年8月已过时，尚未更新。

你需要做很多其他的改变，比如:

将.data替换为.data() 用update替换updateData

2020-09-04 19:35:35

未创建Firebase应用程序“[DEFAULT]”—在Flutter和Firebase中调用Firebase. initializeapp ()

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