颤振网页错误。未捕获的 ReferenceError：未定义 firebase
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【中文标题】颤振网页错误。未捕获的 ReferenceError：未定义 firebase【英文标题】：Flutter Web Error. Uncaught ReferenceError: firebase is not defined 【发布时间】：2021-06-16 08:57:32 【问题描述】：我正在制作一个应用程序并将其放到网络中。但是当我启动它时，在 chrome 中有一个空白屏幕。 chrome 中有我的控制台日志：
Installed new service worker.
zone.dart:1339 Uncaught ReferenceError: firebase is not defined
at Object.ad5 (core.dart:54)
at Object.ajF (cloud_firestore_web.dart:36)
at cloud_firestore_web.dart:29
at ad0.a (async_patch.dart:316)
at ad0.$2 (async_patch.dart:341)
at Object.U (async_patch.dart:246)
at adP (main.dart:10)
at js_helper.dart:2684
at js_helper.dart:2684
at dartProgram (js_helper.dart:2684)
这是我的 main.dart 文件：
import 'package:brew_crew/screens/wrapper.dart';
import 'package:brew_crew/services/auth.dart';
import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:provider/provider.dart';
import 'package:brew_crew/models/user.dart';
void main() async
WidgetsFlutterBinding.ensureInitialized();
await Firebase.initializeApp();
runApp(MyApp());
class MyApp extends StatelessWidget
// This widget is the root of your application.
@override
Widget build(BuildContext context)
return StreamProvider<UserClass>.value(
value: AuthService().user,
child: MaterialApp(
home: Wrapper(),
),
);
还有一个 index.html 文件
<!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
-->
<base href="/">
<meta charset="UTF-8">
<meta content="IE=Edge" http-equiv="X-UA-Compatible">
<meta name="description" content="A new Flutter project.">
<!-- 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="brew_crew">
<link rel="apple-touch-icon" href="icons/Icon-192.png">
<title>brew_crew</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>
</body>
</html>
此外，如果您需要，您可以转到 git 存储库到另一个文件。 https://github.com/rostikro/The-app
我使用的是 Flutter 2.0.2。
【问题讨论】：
你的项目目录中有generated_plugin_registrant.dart吗？
【参考方案1】：
我查看了您的 Github 存储库链接，您的 index.html 缺少 Firebase JS 条目的实现。
您的 pubspec.yaml 文件包含以下依赖项：
firebase_core: ^0.7.0
firebase_auth: ^0.20.1
cloud_firestore: ^0.16.0+1
但您并没有告诉您的 index.html 导入它们。以下导入适用于 firebase_auth 和 cloud_firestore 的 ^1.0.1 版本
<script src="https://www.gstatic.com/firebasejs/7.20.0/firebase-firestore.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.20.0/firebase-app.js"></script>
<script src="https://www.gstatic.com/firebasejs/7.20.0/firebase-auth.js"></script>
请按照文档进行操作，他们对有关 Firebase 和 Flutter 的所有内容进行了非常详尽的解释，特别是 here。您还提到您使用的是 Flutter 2.0.2 版本，所以请注意 null-safety。
【讨论】：
您尝试过这些建议吗？以上是关于颤振网页错误。未捕获的 ReferenceError：未定义 firebase的主要内容，如果未能解决你的问题，请参考以下文章
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