如何在android设备上实现FCM推送通知，即使在游戏被杀的情况下也能工作

implementation 'com.google.firebase:firebase-messaging:22.0.0'

<service
    android:name=".MyFirebaseMessagingService"
    android:exported="false">
    <intent-filter>
        <action android:name="com.google.firebase.MESSAGING_EVENT" />
    </intent-filter>
</service>

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // 处理接收到的消息，并显示通知
    }
}

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        // 处理接收到的消息，并显示通知
        if (remoteMessage.getNotification() != null) {
            String title = remoteMessage.getNotification().getTitle();
            String body = remoteMessage.getNotification().getBody();

            NotificationCompat.Builder builder = new NotificationCompat.Builder(this, "channel_id")
                    .setSmallIcon(R.drawable.notification_icon)
                    .setContentTitle(title)
                    .setContentText(body)
                    .setPriority(NotificationCompat.PRIORITY_DEFAULT);

            NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);
            notificationManager.notify(0, builder.build());
        }
    }
}

if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
    NotificationChannel channel = new NotificationChannel("channel_id", "Channel Name", NotificationManager.IMPORTANCE_DEFAULT);
    NotificationManager notificationManager = getSystemService(NotificationManager.class);
    notificationManager.createNotificationChannel(channel);
}

FirebaseMessaging.getInstance().getToken()
    .addOnCompleteListener(task -> {
        if (!task.isSuccessful()) {
            Log.w("FCM Token", "Fetching FCM registration token failed", task.getException());
            return;
        }

        // 获取设备令牌
        String token = task.getResult();

        // 将设备令牌发送到后端服务器进行注册
        // ...
    });