par*_*096 54 web dart firebase flutter
我正在尝试在 Flutter 集成电子邮件和基于 google 的登录中尝试一个示例项目，并计划使用 firebase 初始化来执行此操作，同时我已按照教程中提到的所有步骤进行操作，一旦尝试使用 firebase，我就会收到此错误已初始化。
"FirebaseOptions cannot be null when creating the default app."
at Object.throw_ [as throw] (http://localhost:7357/dart_sdk.js:5063:11)
at Object.assertFailed (http://localhost:7357/dart_sdk.js:4988:15)
at firebase_core_web.FirebaseCoreWeb.new.initializeApp (http://localhost:7357/packages/firebase_core_web/firebase_core_web.dart.lib.js:252:42)
at initializeApp.next (<anonymous>)
at http://localhost:7357/dart_sdk.js:40192:33
at _RootZone.runUnary (http://localhost:7357/dart_sdk.js:40062:59)
at _FutureListener.thenAwait.handleValue (http://localhost:7357/dart_sdk.js:34983:29)
at handleValueCallback (http://localhost:7357/dart_sdk.js:35551:49)
at Function._propagateToListeners (http://localhost:7357/dart_sdk.js:35589:17)
at _Future.new.[_completeWithValue] (http://localhost:7357/dart_sdk.js:35437:23)
at async._AsyncCallbackEntry.new.callback (http://localhost:7357/dart_sdk.js:35458:35)
at Object._microtaskLoop (http://localhost:7357/dart_sdk.js:40330:13)
at _startMicrotaskLoop (http://localhost:7357/dart_sdk.js:40336:13)
at http://localhost:7357/dart_sdk.js:35811:9
这是我的index.html
<!DOCTYPE html>
<html>
<head>
<!--
If you are serving your web app in a path other than the root, change the
href value below to reflect the base path you are serving from.
The path provided below has to start and end with a slash "/" in order for
it to work correctly.
For more details:
* https://developer.mozilla.org/en-US/docs/Web/HTML/Element/base
This is a placeholder for base href that will be replaced by the value of
the `--base-href` argument provided to `flutter build`.
-->
<base href="$FLUTTER_BASE_HREF">
<meta charset="UTF-8">
<meta content="IE=Edge" http-equiv="X-UA-Compatible">
<meta name="description" content="A new Flutter project.">
<meta name="google-signin-client_id" content="619218114547-xxxx.apps.googleusercontent.com">
<!-- iOS meta tags & icons -->
<meta name="apple-mobile-web-app-capable" content="yes">
<meta name="apple-mobile-web-app-status-bar-style" content="black">
<meta name="apple-mobile-web-app-title" content="signin_example">
<link rel="apple-touch-icon" href="icons/Icon-192.png">
<!-- Favicon -->
<link rel="icon" type="image/png" href="favicon.png"/>
<title>signin_example</title>
<link rel="manifest" href="manifest.json">
</head>
<body>
<!-- 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>
<script type="module">
// Import the functions you need from the SDKs you need
import { initializeApp } from "https://www.gstatic.com/firebasejs/9.6.0/firebase-app.js";
import { getAnalytics } from "https://www.gstatic.com/firebasejs/9.6.0/firebase-analytics.js";
// 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: "xxx",
authDomain: "xxx",
projectId: "xx",
storageBucket: "exxx",
messagingSenderId: "xxx",
appId: "xxx",
measurementId: "xxx"
};
// Initialize Firebase
const app = initializeApp(firebaseConfig);
const analytics = getAnalytics(app);
</script>
</body>
</html>
main.dart 文件中发生 firebase 初始化的部分代码
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(SignUpApp());
}
项目的pubsec.yaml文件
name: signin_example
description: A new Flutter project.
# The following line prevents the package from being accidentally published to
# pub.dev using `flutter pub publish`. This is preferred for private packages.
publish_to: 'none' # Remove this line if you wish to publish to pub.dev
https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
version: 1.0.0+1
environment:
sdk: ">=2.15.0-268.18.beta <3.0.0"
dependencies:
flutter:
sdk: flutter
# 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_auth: ^3.3.0
firebase_core: ^1.10.2
google_sign_in: ^5.2.1
shared_preferences: ^2.0.9
dev_dependencies:
flutter_test:
sdk: flutter
flutter_lints: ^1.0.0
# The following section is specific to Flutter.
flutter:
assets:
- assets/images/
uses-material-design: true
谁能帮我理解这里的问题是什么？
hnn*_*lch 118
更新：
对于您的firebase_core版本来说，一旦您在 flutter 代码中初始化 firebase ，似乎就足以通过FirebaseOptions（并且您不需要在您的 中使用任何脚本标签index.html）：
void main() async {
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp(
// Replace with actual values
options: FirebaseOptions(
apiKey: "XXX",
appId: "XXX",
messagingSenderId: "XXX",
projectId: "XXX",
),
);
runApp(MyApp());
}
或者，您还可以按照更新的官方文档并使用 Firebase CLI 自动firebase_options.dart在您的文件夹中创建一个文件，该文件将为您lib定义正确的文件。FirebaseOptions步骤是：
dart pub global activate flutterfire_cli
flutterfire configure
firebase_options.dart文件导入到您的main.dart文件中并初始化，Firebase如下所示：dart pub global activate flutterfire_cli
以前的答案：
来自文档：
当前将 Firebase SDK 添加到 Flutter Web 项目的唯一方法是从 Firebase 内容分发网络 (CDN) 导入脚本。
因此，请尝试使用脚本标签导入相关的 Firebase 组件，其版本8.6.1如下所示（更多信息请参见此处）：
flutterfire configure
小智 7
将 Web 功能添加到 Flutter 应用程序中，我们需要在 的 options 参数中提供值Firebase.initializeApp(options:FirebaseOptions...)。
这些值是我们在 Firebase 控制台中添加 Web 应用程序时获得的值。我所做的是config/config.dart在文件夹中创建文件lib。在哪里：
class Configurations {
static const _apiKey = "Your values";
static const _authDomain = "Your values";
static const _projectId = "Your values";
static const _storageBucket = "Your values"
static const _messagingSenderId ="Your values"
static const _appId = "Your values"
//Make some getter functions
String get apiKey => _apiKey;
String get authDomain => _authDomain;
String get projectId => _projectId;
String get storageBucket => _storageBucket;
String get messagingSenderId => _messagingSenderId;
String get appId => _appId;
}
然后将config文件夹添加到.gitignore.
lib/config
现在将文件导入相关部分，然后
import 'config/config.dart';
final configurations = Configurations();
Future<void> init() async {
await Firebase.initializeApp(
options: FirebaseOptions(
apiKey: configurations.apiKey,
appId: configurations.appId,
messagingSenderId: configurations.messagingSenderId,
projectId: configurations.projectId));
现在应该可以了。
我也遇到了这个问题。对我有用的修复是：
在我的main()我lib/main.dart改变了
Future<void> main() async {
await Firebase.initializeApp();
runApp(const MyApp());
}
到
Future<void> main() async {
await Firebase.initializeApp(options: DefaultFirebaseOptions.currentPlatform);
runApp(const MyApp());
}
现在它对我有用！
只需确保激活 flutter cli（参见第 5 段答案）并运行flutterfire configure.
完成所有操作后，请确保lib/firebase_options.dart已生成。
将其添加到您的 main.dart 文件和 main 方法中
WidgetsFlutterBinding.ensureInitialized();
if (kIsWeb)
await Firebase.initializeApp(
options: FirebaseOptions(
apiKey: "your key",
appId: "your key",
messagingSenderId: "your key",
projectId: "your key",
),
);
else
await Firebase.initializeApp();
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