如何使用后台服务 Flutter？答案

【问题标题】：How to work with background services Flutter?如何使用后台服务 Flutter？
【发布时间】：2022-12-12 19:46:44
【问题描述】：

您好我正在尝试创建一个 flutter 应用程序，即使在应用程序关闭时也会显示通知。

我设法找到了一些与那个东西相关的插件flutter_background_service，但是当我尝试复制示例中显示的代码时，它显示了一些与 AndroidServiceInstance 和 setAsBackgroundService() 相关的错误，说它们未定义。如何解决这个问题？有没有更好的方法来实现我想要的？谢谢之前。

这是我当前的代码：

Future<void> initializeService() async {
  final service = FlutterBackgroundService();

  const AndroidNotificationChannel channel = AndroidNotificationChannel(
    notificationChannelId, // ID
    'MY FOREGROUND SERVICE', // Title
    description:
    'This channel is used for important notifications.', // Description
    importance: Importance.low, // importance must be at low or higher level
  );

  final FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();

  if (Platform.isIOS) {
    await flutterLocalNotificationsPlugin.initialize(
      const InitializationSettings(
        iOS: IOSInitializationSettings(),
      ),
    );
  }

  await flutterLocalNotificationsPlugin
      .resolvePlatformSpecificImplementation<
      AndroidFlutterLocalNotificationsPlugin>()
      ?.createNotificationChannel(channel);

  await service.configure(
    androidConfiguration: AndroidConfiguration(
      onStart: onStart,
      autoStart: true,
      isForegroundMode: true,

      notificationChannelId: 'my_foreground',
      initialNotificationTitle: 'AWESOME SERVICE',
      initialNotificationContent: 'Initializing',
      foregroundServiceNotificationId: 888,
    ),

    iosConfiguration: IosConfiguration(
      autoStart: true,
      onForeground: onStart,
      onBackground: onIosBackground,
    ),
  );
  service.startService();
}

onStart(ServiceInstance service) async {
  DartPluginRegistrant.ensureInitialized();

  if (service is AndroidServiceInstance) {
    service.on('setAsForeground').listen((event) {
      service.setAsForegroundService();
    });
    service.on('setAsBackground').listen((event) {
      service.setAsBackgroundService();
    });
  }
  service.on('stopService').listen((event) {
    service.stopSelf();
  });
}

【问题讨论】：

标签： flutter

【解决方案1】：

最终 FlutterLocalNotificationsPlugin flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin(); final AndroidInitializationSettings initializationSettingsAndroid = AndroidInitializationSettings('@mipmap/ic_launcher'); final InitializationSettings 初始化设置 = InitializationSettings(android: initializationSettingsAndroid); 等待 flutterLocalNotificationsPlugin.initialize(initializationSettings, onSelectNotification: (payload) 异步 => handleLocalNotification（有效载荷，消息：消息））; debugPrint('在前台收到消息！'); const AndroidNotificationChannel 通道 = AndroidNotificationChannel( 'high_importance_channel', // id '高重要性通知', // titledescription 重要性：Importance.max， ); 等待 flutterLocalNotificationsPlugin .resolvePlatformSpecificImplementation< AndroidFlutterLocalNotificationsPlugin>() ?.createNotificationChannel(频道); RemoteNotification notification = message.notification!; AndroidNotification android = message.notification!.android!;

【讨论】：