应用程序在前台时如何处理Firebase通知

Question

我已将Firebase Cloud Messaging与我的应用程序集成在一起。 当我从Firebase控制台发送通知时，如果该应用程序在后台或未打开，则我会成功收到该通知，否则，如果该应用程序在前台或已打开，则不会收到该通知。

所有建议表示赞赏。

Answer 1

当应用程序处于前台时，不会自行生成通知。 您需要编写一些其他代码。 收到消息后，将调用onMessageReceived()方法，您可以在其中生成通知。 这是代码：

public class MyFirebaseMessagingService extends FirebaseMessagingService {
    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);
        Log.d("msg", "onMessageReceived: " + remoteMessage.getData().get("message"));
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, PendingIntent.FLAG_ONE_SHOT);
        String channelId = "Default";
        NotificationCompat.Builder builder = new  NotificationCompat.Builder(this, channelId)
                .setSmallIcon(R.mipmap.ic_launcher)
                .setContentTitle(remoteMessage.getNotification().getTitle())
                .setContentText(remoteMessage.getNotification().getBody()).setAutoCancel(true).setContentIntent(pendingIntent);;
        NotificationManager manager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            NotificationChannel channel = new NotificationChannel(channelId, "Default channel", NotificationManager.IMPORTANCE_DEFAULT);
            manager.createNotificationChannel(channel);
        }
        manager.notify(0, builder.build());
    }
}

Answer 2

当应用程序处于前台状态时， FirebaseMessagingService永远无法工作。 在这种情况下，如果您想从FCM接收消息，则WakefulBroadcastReceiver将为您工作

public class FirebaseDataReceiver extends WakefulBroadcastReceiver {


        @Override
        public void onReceive(Context context, Intent intent) {

            Log.d("BroadcastReceiver::", "BroadcastReceiver");
            NotificationCompat.Builder builder = new NotificationCompat.Builder(context)
                    .setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle(intent.getExtras().getString("title"))
                    .setContentText(intent.getExtras().getString("message"));
            NotificationManager manager = (NotificationManager) context.getSystemService(NOTIFICATION_SERVICE);
            manager.notify(0, builder.build());
        }
    }

将firebase与Play商店中的GCM链接，并在清单中编写以下代码

<receiver
    android:name=".firebase.FirebaseDataReceiver"
    android:exported="true"
    android:permission="com.google.android.c2dm.permission.SEND">
    <intent-filter>
        <action android:name="com.google.android.c2dm.intent.RECEIVE" />
    </intent-filter>
</receiver>