Flutter升级后Firebase无法创建新用户及空指针异常求助

问题描述 #

升级Flutter版本后，Firebase无法创建新用户，抛出以下空指针异常：

E/flutter (22614): at io.flutter.plugins.firebase.core.FlutterFirebaseCorePlugin$$ExternalSyntheticLambda3.run(Unknown Source:6)
E/flutter (22614): ... 3 more
E/flutter (22614): Caused by: java.util.concurrent.ExecutionException: java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.firebase.auth.FirebaseUser com.google.firebase.auth.FirebaseAuth.getCurrentUser()' on a null object reference
E/flutter (22614): at com.google.android.gms.tasks.Tasks.zza(com.google.android.gms:play-services-tasks@@18.1.0:5)
E/flutter (22614): at com.google.android.gms.tasks.Tasks.await(com.google.android.gms:play-services-tasks@@18.1.0:9)
E/flutter (22614): at io.flutter.plugins.firebase.core.FlutterFirebasePluginRegistry.lambda$getPluginConstantsForFirebaseApp$0(FlutterFirebasePluginRegistry.java:55)
E/flutter (22614): at io.flutter.plugins.firebase.core.FlutterFirebasePluginRegistry$$ExternalSyntheticLambda1.run(Unknown Source:4)
E/flutter (22614): ... 3 more
E/flutter (22614): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.firebase.auth.FirebaseUser com.google.firebase.auth.FirebaseAuth.getCurrentUser()' on a null object reference
E/flutter (22614): at io.flutter.plugins.firebase.auth.FlutterFirebaseAuthPlugin.lambda$getPluginConstantsForFirebaseApp$16(FlutterFirebaseAuthPlugin.java:689)

解决方案 #

• 修正初始化顺序：异常核心是FirebaseAuth实例未初始化就调用了getCurrentUser()，需确保在使用Auth功能前完成Firebase核心初始化：

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

• 同步Firebase插件版本：Flutter升级后，需保证firebase_core和firebase_auth等插件版本与当前Flutter兼容，在pubspec.yaml中统一指定版本后执行flutter pub get：

  dependencies:
    flutter:
      sdk: flutter
    firebase_core: ^2.15.0
    firebase_auth: ^4.10.0
  

• 清理项目缓存：执行flutter clean，删除android/.gradle、android/build目录后重新运行项目，避免缓存导致的版本冲突。

• 检查Android配置文件：确认android/app/google-services.json为最新版本，包名与Firebase控制台一致；同时检查android/build.gradle和android/app/build.gradle中的Firebase依赖版本同步。

• 延迟Auth操作：所有Firebase Auth相关操作（如创建用户）必须在Firebase.initializeApp()完成后执行，禁止在初始化流程未结束前提前调用。

内容的提问来源于stack exchange，提问作者Adam Obonyilo