Flutter项目Firebase初始化失败求助（已调用initializeApp）

我正在搭建Firebase Auth，已经完成相关步骤，但作为新手，发现YouTube上的教程大多基于旧版本，而build.gradle的应用级和项目级配置已有变更。我认为已完成大部分配置，但仍出现Firebase应用初始化错误，想知道问题可能出在哪里，以及当前该如何解决？

main.dart 代码 #

import 'package:ecom/signup.dart';
import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import 'provider/cart_provider.dart';
import 'provider/favourite_provider.dart';

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

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  try {
    print("Firebase initialized successfully");
    await Firebase.initializeApp();
  } catch (e) {
    print("Failed to initialize Firebase: $e");
  }
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) => MultiProvider(
        providers: [
          ChangeNotifierProvider(create: (_) => CartProvider()),
          ChangeNotifierProvider(create: (_) => FavoriteProvider()),
        ],
        child: MaterialApp(
          title: 'Flutter Demo',
          debugShowCheckedModeBanner: false,
          theme: ThemeData(
            colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
            useMaterial3: true,
          ),
          home: const sign_up(),
        ),
      );
}

Gradle 相关配置 #

项目级 build.gradle #

allprojects {
    repositories {
        google()
        mavenCentral()
    }
}

rootProject.buildDir = "../build"
subprojects {
    project.buildDir = "${rootProject.buildDir}/${project.name}"
}
subprojects {
    project.evaluationDependsOn(":app")
}

tasks.register("clean", Delete) {
    delete rootProject.buildDir
}

应用级 build.gradle #

plugins {
    id "com.android.application"
    id "kotlin-android"
    id "dev.flutter.flutter-gradle-plugin"
    id 'com.google.gms.google-services'
}

def localProperties = new Properties()
def localPropertiesFile = rootProject.file("local.properties")
if (localPropertiesFile.exists()) {
    localPropertiesFile.withReader("UTF-8") { reader ->
        localProperties.load(reader)
    }
}

def flutterVersionCode = localProperties.getProperty("flutter.versionCode")
if (flutterVersionCode == null) {
    flutterVersionCode = "1"
}

def flutterVersionName = localProperties.getProperty("flutter.versionName")
if (flutterVersionName == null) {
    flutterVersionName = "1.0"
}

android {
    namespace = "com.example.ecom"
    compileSdk = flutter.compileSdkVersion
    ndkVersion = flutter.ndkVersion

    compileOptions {
        sourceCompatibility = JavaVersion.VERSION_1_8
        targetCompatibility = JavaVersion.VERSION_1_8
    }

    defaultConfig {
       
        applicationId = "com.example.ecom"
        minSdk = 23
        targetSdk = flutter.targetSdkVersion
        versionCode = flutterVersionCode.toInteger()
        versionName = flutterVersionName
    }

    buildTypes {
        release {

            signingConfig = signingConfigs.debug
        }
    }
}

flutter {
    source = "../../"
}

dependencies{
    implementation platform('com.google.firebase:firebase-bom:33.1.2')
    implementation 'com.google.firebase:firebase-analytics'
}

apply plugin: 'com.google.gms.google-services'

settings.gradle #

pluginManagement {
    def flutterSdkPath = {
        def properties = new Properties()
        file("local.properties").withInputStream { properties.load(it) }
        def flutterSdkPath = properties.getProperty("flutter.sdk")
        assert flutterSdkPath != null, "flutter.sdk not set in local.properties"
        return flutterSdkPath
    }()

    includeBuild("$flutterSdkPath/packages/flutter_tools/gradle")

    repositories {
        google()
        mavenCentral()
        gradlePluginPortal()
    }
}

plugins {
    id "dev.flutter.flutter-plugin-loader" version "1.0.0"
    id "com.android.application" version "7.3.0" apply false
    id "org.jetbrains.kotlin.android" version "2.0.10" apply false
    id 'com.google.gms.google-services' version '4.4.2' apply false
}

include ":app"

排查与解决步骤 #

1. 检查 google-services.json 文件 #

• 确认 android/app 目录下存在该文件，且是从Firebase控制台下载的对应项目文件。
• 核对文件内的 package_name 与应用级build.gradle中的 applicationId（com.example.ecom）完全一致。

2. 修正Firebase初始化逻辑 #

当前代码的成功提示在初始化前打印，逻辑错误，调整为：

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  try {
    await Firebase.initializeApp();
    print("Firebase initialized successfully");
  } catch (e) {
    print("Failed to initialize Firebase: $e");
  }
  runApp(const MyApp());
}

3. 添加Firebase Auth依赖 #

• 在应用级build.gradle的dependencies块中添加Auth依赖：

  implementation 'com.google.firebase:firebase-auth'
  

• 在项目的pubspec.yaml中添加Flutter端的Auth依赖：

  dependencies:
    flutter:
      sdk: flutter
    firebase_core: ^2.24.2
    firebase_auth: ^4.16.0
    provider: ^6.1.1
  

• 执行 flutter pub get 同步依赖。

4. 清理并重构项目 #

依次执行以下命令：

flutter clean
flutter pub get

重启开发工具后重新运行项目。

5. 验证版本兼容性 #

检查firebase_core、firebase_auth版本与当前Flutter版本是否兼容，可参考pub.dev上的版本说明调整。

内容的提问来源于stack exchange，提问作者M Tashkeel Pasha