使用WorkManager与Firebase发送推送通知时遇初始化错误求助

我正在使用Firebase Cloud Messaging发送推送通知，希望通过WorkManager包实现通知调度。之前尝试过flutter_local_notification包的zoneSchedule方法，但该方法会在应用首次启动时就发送通知。现在遇到如下错误：

D/EGL_emulation( 6738): eglCreateContext: 0xe91a9600: maj 2 min 0 rcv 2
D/EGL_emulation( 6738): eglCreateContext: 0xe91a9a60: maj 2 min 0 rcv 2
D/HostConnection( 6738): HostConnection::get() New Host Connection established 0xe919c6a0, tid 6952
D/HostConnection( 6738): HostComposition ext ANDROID_EMU_CHECKSUM_HELPER_v1 ANDROID_EMU_native_sync_v2 ANDROID_EMU_native_sync_v3 ANDROID_EMU_native_sync_v4 ANDROID_EMU_dma_v1 ANDROID_EMU_direct_mem ANDROID_EMU_YUV_Cache ANDROID_EMU_has_shared_slots_host_memory_allocator ANDROID_EMU_sync_buffer_data ANDROID_EMU_read_color_buffer_dma GL_OES_vertex_array_object GL_KHR_texture_compression_astc_ldr ANDROID_EMU_host_side_tracing ANDROID_EMU_gles_max_version_2
D/EGL_emulation( 6738): eglMakeCurrent: 0xe91a9a60: ver 2 0 (tinfo 0xcad2bc10) (first time)
E/BackgroundWorker( 6738): errorCode: error, errorMessage: [core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()
I/WM-WorkerWrapper( 6738): Worker result FAILURE for Work [ id=0099bb1f-670e-4711-9fc2-7b95f118ca6e, tags={ be.tramckrijte.workmanager.BackgroundWorker } ]

相关代码文件 #

main.dart #

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  await FlutterDownloader.initialize(debug: true);
  tz.initializeTimeZones();
  await Workmanager().initialize(callbackDispatcher,isInDebugMode: true);
  await GetStorage.init();
  runApp(const MyApp());
}
@pragma('vm:entry-point')
Future<void> backgroundMessageHandler(RemoteMessage message) async {
  await Firebase.initializeApp();
  print("backgroundMessageHandler");
}

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

  @override
  Widget build(BuildContext context) {
    return GetMaterialApp(
      title: 'Flutter Demo',
      locale: HandleLocale().getLocale(),
      translations: LocaleString(),
      showSemanticsDebugger: false,
      debugShowCheckedModeBanner: false,
      theme: Themes().lightTheme,
      darkTheme: Themes().darkTheme,
      themeMode: ThemeServices().getThemeMode(),
      home: const MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key});

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  myController controller = Get.put(myController());

  @override
  void initState() {
    super.initState();

    NotificationHandler().getToken().then((value){
      print(value);
    });
    Workmanager().registerOneOffTask(
      '1',
      'simpleTask',
      initialDelay: const Duration(seconds: 10),
    );

    NotificationHandler().initMessage(context);
    NotificationHandler().interactMessage(context);
    isAlreadyLoggedIn();
  }

  Future<void> isAlreadyLoggedIn() async {
    final value = await controller.getUserInfo();
    print(value.toList());
    if (value.isEmpty) {
      Navigator.push(
          context, MaterialPageRoute(builder: (context) => const LoginPage()));
    }
  }

  @override
  Widget build(BuildContext context) {
    return const PageHandler();
  }
}

callbackdispatcher.dart #

void callbackDispatcher() {
  Workmanager().executeTask((taskName, inputData) async {
    // This is where you can schedule your notifications at the desired time
    final token = await NotificationHandler().getToken();
    NotificationHandler().scheduleNotification(token);
    return Future.value(true);
  });
}

根目录build.gradle #

buildscript {
    ext.kotlin_version = '1.7.10'
    repositories {
        google()
        mavenCentral()
    }

    dependencies {
        classpath 'com.android.tools.build:gradle:7.3.0'
        classpath"com.google.gms:google-services:4.3.15"
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
    }
}

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
}

android/build.gradle #

plugins {
    id "com.android.application"
    id "kotlin-android"
    id "dev.flutter.flutter-gradle-plugin"
}

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.income_and_expenditure_app"
    compileSdkVersion flutter.compileSdkVersion
    ndkVersion flutter.ndkVersion

    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }

    kotlinOptions {
        jvmTarget = '1.8'
    }

    sourceSets {
        main.java.srcDirs += 'src/main/kotlin'
    }

    defaultConfig {
        applicationId "com.example.income_and_expenditure_app"
        minSdkVersion flutter.minSdkVersion
        targetSdkVersion flutter.targetSdkVersion
        multiDexEnabled true
        versionCode flutterVersionCode.toInteger()
        versionName flutterVersionName
    }

    buildTypes {
        release {
            signingConfig signingConfigs.debug
        }
    }
}

flutter {
    source '../..'
}
apply plugin:"com.google.gms.google-services"
apply plugin:'com.android.application'
dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
    implementation("com.google.firebase:firebase-analytics-ktx")
    implementation(platform("com.google.firebase:firebase-bom:32.3.1"))
    implementation 'com.google.firebase:firebase-auth'
}

1. 修复Firebase未初始化问题 #

WorkManager的回调运行在独立的后台隔离区，不会共享主应用的Firebase初始化状态，必须在回调内部重新初始化Firebase：

修改callbackdispatcher.dart：

void callbackDispatcher() {
  Workmanager().executeTask((taskName, inputData) async {
    // 后台任务中重新初始化Firebase
    await Firebase.initializeApp();
    // 执行通知逻辑
    final token = await NotificationHandler().getToken();
    NotificationHandler().scheduleNotification(token);
    return Future.value(true);
  });
}

2. 解决flutter_local_notifications的zoneSchedule首次启动触发问题 #

如果继续使用zoneSchedule，需避免在应用启动时直接调用，可通过本地存储标记是否已调度，或仅在用户交互后触发：

Future<void> setupScheduledNotification() async {
  final storage = GetStorage();
  final isScheduled = storage.read('notification_scheduled') ?? false;
  
  if (!isScheduled) {
    await flutterLocalNotificationsPlugin.zonedSchedule(
      0,
      '通知标题',
      '通知内容',
      // 设置目标触发时间，例如明天当前时间
      tz.TZDateTime.now(tz.local).add(const Duration(days: 1)),
      const NotificationDetails(
        android: AndroidNotificationDetails('schedule_channel', '定时通知'),
      ),
      androidAllowWhileIdle: true,
      uiLocalNotificationDateInterpretation:
          UILocalNotificationDateInterpretation.absoluteTime,
    );
    storage.write('notification_scheduled', true);
  }
}

3. 依赖兼容性检查 #

确保flutter_workmanager与Firebase BOM版本兼容，当前配置的Firebase BOM 32.3.1属于稳定版本，无需额外调整。

内容的提问来源于stack exchange，提问作者Jeevan Shrestha