Flutter集成Firebase Messaging后前台推送通知不显示后台正常如何解决

问题根因 #

NotificationService类的初始化逻辑存在实例冲突问题：initialize方法内重新定义了一个局部的FlutterLocalNotificationsPlugin实例做初始化，而前台调用showNotification方法时使用的是类静态的未初始化的_flutterLocalNotificationsPlugin实例，导致通知无法弹出。

修复方案 #

1. 修正NotificationService初始化逻辑 #

修改NotificationService.dart代码，删除局部重复实例定义，直接使用类静态实例完成初始化：

class NotificationService {
  static final FlutterLocalNotificationsPlugin
      _flutterLocalNotificationsPlugin = FlutterLocalNotificationsPlugin();

  static Future initialize() async {
    AndroidInitializationSettings androidInitializationSettings =
        AndroidInitializationSettings('@mipmap/ic_launcher');

    InitializationSettings initializationSettings =
        InitializationSettings(android: androidInitializationSettings);

    await _flutterLocalNotificationsPlugin.initialize(
      initializationSettings,
      // onSelectNotification: doSomething(),
    );
  }

  static Future showNotification(RemoteMessage message) async {
    AndroidNotificationDetails androidDetails = AndroidNotificationDetails(
      "default_notification_channel_id",
      "channel",
      enableLights: true,
      enableVibration: true,
      priority: Priority.high,
      importance: Importance.max,
      largeIcon: DrawableResourceAndroidBitmap("ic_launcher"),
      styleInformation: MediaStyleInformation(
        htmlFormatContent: true,
        htmlFormatTitle: true,
      ),
      playSound: true,
    );

    await _flutterLocalNotificationsPlugin.show(
        message.data.hashCode,
        message.data['title'],
        message.data['body'],
        NotificationDetails(
          android: androidDetails,
        ));
  }
}

2. 适配Android 13+通知权限 #

Android 13及以上系统需要主动申请通知权限才能弹出本地通知：

• 在AndroidManifest.xml中新增权限声明：

<uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>

• 应用启动时主动申请权限，可通过permission_handler插件实现：

// 放在initState中初始化通知服务之前执行
if (Platform.isAndroid) {
  final status = await Permission.notification.request();
  if (status.isDenied) {
    // 可自行添加权限被拒的提示逻辑
  }
}

3. 验证回调与渠道配置 #

1. 在FirebaseMessaging.onMessage.listen回调中添加打印日志，确认前台收到消息时回调正常触发：

FirebaseMessaging.onMessage.listen((RemoteMessage message) {
  print("前台收到消息：${message.data}");
  NotificationService.showNotification(message);
});

2. 检查res/values/strings.xml中的default_notification_channel_id取值，和代码中AndroidNotificationDetails的第一个参数完全一致，避免渠道不匹配导致通知无法弹出。

内容的提问来源于stack exchange，提问作者user17091737