未显示前景上的通知android（奥利奥）

Question

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    @Override
    public void onMessageReceived(final RemoteMessage remoteMessage) {
        Timber.d("FCM-From: " + remoteMessage.getFrom());

            new Handler(Looper.getMainLooper()).post(new Runnable() {
                public void run() {
                    if (remoteMessage.getNotification() != null) {
                        Timber.d("FCM-Message Notification Body: " + remoteMessage.getNotification().getBody());

                        NotificationCompat.Builder builder = new  NotificationCompat.Builder(
                                getApplicationContext(), "CHANNEL_NOTIF")
                                .setSmallIcon(R.mipmap.ic_launcher)
                                .setContentTitle("test")
                                .setContentText("test content");
                        NotificationManager manager = (NotificationManager)     getSystemService(NOTIFICATION_SERVICE);
                        if (manager != null) {
                            Timber.d("FCM-Notif");
                            manager.notify(1, builder.build());
                        }
                    }
                }
            });
    }
}

Answer 1

发生这种情况是因为Android Oreo和更高的API级别。因此，在Android8.0或更高版本上发布任何通知之前，必须创建通知通道，您应该在应用程序启动后立即执行此代码。重复调用它是安全的，因为创建一个现有的通知通道不执行任何操作。

public class MyFirebaseMessagingService extends FirebaseMessagingService {

    private static final String TAG = MyFirebaseMessagingService.class.getSimpleName();
    private NotificationUtils notificationUtils;
    private String title,message,click_action;
    private  String CHANNEL_ID = "MyApp";

    @Override
    public void onMessageReceived(RemoteMessage remoteMessage) {

        // Check if message contains a data payload.
        if (remoteMessage.getData().size() > 0) {

            try {
                JSONObject data = new JSONObject(remoteMessage.getData());
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }

        // Check if message contains a notification payload.
        if (remoteMessage.getNotification() != null) {
             title = remoteMessage.getNotification().getTitle(); //get title
             message = remoteMessage.getNotification().getBody(); //get message
             click_action = remoteMessage.getNotification().getClickAction(); //get click_action

            Log.d(TAG, "Notification Title: " + title);
            Log.d(TAG, "Notification Body: " + message);
            Log.d(TAG, "Notification click_action: " + click_action);

            sendNotification(title, message,click_action);
        }
    }

    private void sendNotification(String title,String messageBody, String click_action) {
        Intent intent = new Intent(this, TargetActivity.class);
        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);

        PendingIntent pendingIntent = PendingIntent.getActivity(this, 0, intent, 0);

        NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(this, CHANNEL_ID)
                .setSmallIcon(R.drawable.logo_heart)
                .setContentTitle(title)
                .setContentText(messageBody)
                .setPriority(NotificationCompat.PRIORITY_DEFAULT)
                .setContentIntent(pendingIntent)// Set the intent that will fire when the user taps the notification
                .setAutoCancel(true);

        NotificationManagerCompat notificationManager = NotificationManagerCompat.from(this);

        // notificationId is a unique int for each notification that you must define
        notificationManager.notify(1, mBuilder.build());

        createNotificationChannel();
    }

    private void createNotificationChannel() {
        // Create the NotificationChannel, but only on API 26+ because
        // the NotificationChannel class is new and not in the support library
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
            CharSequence name = getString(R.string.app_name);
            String description = getString(R.string.description);
            int importance = NotificationManager.IMPORTANCE_DEFAULT;
            NotificationChannel channel = new NotificationChannel(CHANNEL_ID, name, importance);
            channel.setDescription(description);
            // Register the channel with the system; you can't change the importance or other notification behaviors after this
            NotificationManager notificationManager = getSystemService(NotificationManager.class);
            notificationManager.createNotificationChannel(channel);
        }
    }

}