应用程式被杀死时未收到Firebase通知

Question

经过大量研究，我正确地实施了FCM，即我使用了数据有效负载而不是通知。我已经添加了完整的代码，请告诉我我在哪里出错？

MyFirebaseInstanceService：

package com.example.student.notitest.Service;

import android.app.Notification; import android.app.NotificationChannel; import android.app.NotificationManager; import android.content.Context; import android.graphics.Color; import android.os.Build; import android.support.v4.app.NotificationCompat; import android.util.Log;

import com.example.student.notitest.R; import com.google.firebase.iid.FirebaseInstanceIdService; import com.google.firebase.messaging.FirebaseMessagingService; import com.google.firebase.messaging.RemoteMessage;

import java.util.Map; import java.util.Random;

public class MyFirebaseInstanceService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {
        super.onMessageReceived(remoteMessage);

        if (remoteMessage.getData().isEmpty())
        showNotification(remoteMessage.getNotification().getTitle(),remoteMessage.getNotification().getBody());
        else
            showNotification(remoteMessage.getData());
    }

    private void showNotification(Map<String, String> data) {


        String title = data.get("title").toString();
        String body = data.get("body").toString();

        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "com.example.student.notitest";

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,"Notification",
                    NotificationManager.IMPORTANCE_HIGH);

            notificationChannel.setDescription("Quiz App");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.GREEN);
            notificationManager.createNotificationChannel(notificationChannel);

        }
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this,NOTIFICATION_CHANNEL_ID);
        notificationBuilder.setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_ALL)
                .setWhen(System.currentTimeMillis())
                .setSmallIcon(R.drawable.ic_notification)
                .setTicker("India Quiz")
                .setContentTitle(title)
                .setContentText(body)
                .setContentInfo("info");
        notificationManager.notify(new Random().nextInt(),notificationBuilder.build());

    }

    private void showNotification(String title, String body) {

        NotificationManager notificationManager = (NotificationManager)getSystemService(Context.NOTIFICATION_SERVICE);
        String NOTIFICATION_CHANNEL_ID = "com.example.student.notitest";

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O){
            NotificationChannel notificationChannel = new NotificationChannel(NOTIFICATION_CHANNEL_ID,"Notification",
                    NotificationManager.IMPORTANCE_DEFAULT);

            notificationChannel.setDescription("India Quiz App Notifications Here");
            notificationChannel.enableLights(true);
            notificationChannel.setLightColor(Color.GREEN);

            notificationManager.createNotificationChannel(notificationChannel);

        }
        NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(this,NOTIFICATION_CHANNEL_ID);
        notificationBuilder.setAutoCancel(true)
                .setDefaults(Notification.DEFAULT_ALL)
                .setWhen(System.currentTimeMillis())
                .setSmallIcon(R.drawable.ic_notification)
                .setTicker("India Quiz")
                .setContentTitle(title)
                .setContentText(body)
                .setContentInfo("info");
        notificationManager.notify(new Random().nextInt(),notificationBuilder.build());


    }

    @Override
    public void onNewToken(String s) {
        super.onNewToken(s);

        Log.d("TOKENFIREBASE",s);
    } }

我也尝试过通过REST客户端（即ARC（谷歌扩展））发送通知，但没有成功。请帮忙，因为在同一主题上进行编码已超过3天，但仍未找到任何解决方案。 请帮忙！