Как реализовать уведомления MediaStyle для поддержки Android Oreo?

Question

В моем приложении для Android, над которым я работаю, я реализовал класс обслуживания MediaPlayer (PlayService.java), который будет воспроизводить потоковый аудиосигнал в реальном времени с удаленного источника.Когда служба работает на переднем плане, она отображает уведомление с управлением воспроизведением / приостановкой воспроизведения мультимедиа, так что пользователь также может обрабатывать действия медиаплеера оттуда.Я преуспел в этом, и я протестировал свое приложение на используемых в настоящее время версиях Android (т.е. Jellybean, Kitkat, Lollipop, Marshmallow и Nougat).Приложение с уведомлением работает должным образом, но мое приложение не отображает уведомление в версии Android 8.0 (Oreo).Я много исследовал и перепробовал несколько ссылок, таких как https://medium.com/androiddevelopers/migrating-mediastyle-notifications-to-support-android-o-29c7edeca9b7, но не смог найти правильного решения.

Мой рабочий код для класса обслуживания MediaPlayer:

public class PlayService extends Service implements MediaPlayer.OnCompletionListener,MediaPlayer.OnPreparedListener,
        MediaPlayer.OnErrorListener,MediaPlayer.OnSeekCompleteListener,MediaPlayer.OnInfoListener,
        MediaPlayer.OnBufferingUpdateListener,AudioManager.OnAudioFocusChangeListener  {

    private AudioManager audioManager;
    private MediaPlayer mediaPlayer = new MediaPlayer();
    private String sentAudioLink="";

    //Used to pause/resume MediaPlayer
    private int resumePosition;

    //Handle notification in system tray
    private NotificationCompat.Builder builder;
    private NotificationManager notificationManager;
    private int notification_id;
    private RemoteViews remoteViews;

    public static final String ACTION_PLAY = "com.example.ACTION_PLAY";
    public static final String ACTION_PAUSE = "com.example.ACTION_PAUSE";
    public static final String ACTION_STOP = "com.example.ACTION_STOP";

    //MediaSession
    private MediaSessionManager mediaSessionManager;
    private MediaSessionCompat mediaSession;
    private MediaControllerCompat.TransportControls transportControls;

    //AudioPlayer notification ID
    private static final int NOTIFICATION_ID = 101;

    @Override
    public void onCreate() {
        mediaPlayer.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
        mediaPlayer.setOnCompletionListener(this);
        mediaPlayer.setOnPreparedListener(this);
        mediaPlayer.setOnErrorListener(this);
        mediaPlayer.setOnSeekCompleteListener(this);
        mediaPlayer.setOnInfoListener(this);
        mediaPlayer.setOnBufferingUpdateListener(this);
        mediaPlayer.reset();
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Bundle bundle = intent.getExtras();
        if (bundle != null)
        {
            sentAudioLink = intent.getExtras().getString("sentAudioLink");
        }

        mediaPlayer.reset();
        //setup the media player data source using the strAudioLink value
        if (!mediaPlayer.isPlaying()) {
            try {
                mediaPlayer.setDataSource(sentAudioLink);
                //prepare media player
                mediaPlayer.prepareAsync();
            } catch (IllegalStateException e) {
                Log.e("workingerror1", e.toString());
                stopSelf();
            } catch (IllegalArgumentException e) {
                Log.e("workingerror2", e.toString());
                stopSelf();
            } catch (IOException e) {
                Log.e("workingerror3", e.toString());
                stopSelf();
            }
            buildNotification(PlaybackStatus.PLAYING);
        }
        //Handle Intent action from MediaSession.TransportControls
        handleIncomingActions(intent);
        return START_STICKY;
    }

    @Override
    public void onDestroy() {
        super.onDestroy();

        if (mediaPlayer != null) {
            removeNotification();
            mediaPlayer.stop();
            mediaPlayer.release();
            mediaPlayer=null;
        }
    }

    @Override
    public void onBufferingUpdate(MediaPlayer mp, int percent) {

    }

    @Override
    public void onCompletion(MediaPlayer mp) {
        stopMedia();
        stopSelf();
        buildNotification(PlaybackStatus.PAUSED);
    }

    public void stopMedia() {
        if (mediaPlayer.isPlaying())
            mediaPlayer.stop();
    }

    @Override
    public boolean onError(MediaPlayer mp, int what, int extra) {
        return false;
    }

    @Override
    public boolean onInfo(MediaPlayer mp, int what, int extra) {
        return false;
    }

    @Override
    public void onPrepared(MediaPlayer mp) {
        playMedia();
    }

    public void playMedia() {
        if (!mediaPlayer.isPlaying() && sentAudioLink!="") {
            mediaPlayer.start();
        }
    }

    @Override
    public void onSeekComplete(MediaPlayer mp) {

    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }


    private void buildNotification(PlaybackStatus playbackStatus) {

        int notificationAction = android.R.drawable.ic_media_pause;//needs to be initialized
        PendingIntent play_pauseAction = null;

        //PendingIntent contentIntent = PendingIntent.getActivity(this, 0,new Intent(this, MainActivity.class), PendingIntent.FLAG_UPDATE_CURRENT);

        //Build a new notification according to the current state of the MediaPlayer
        if (playbackStatus == PlaybackStatus.PLAYING) {
            notificationAction = android.R.drawable.ic_media_pause;
            //create the pause action
            play_pauseAction = playbackAction(1);
        } else if (playbackStatus == PlaybackStatus.PAUSED) {
            notificationAction = android.R.drawable.ic_media_play;
            //create the play action
            play_pauseAction = playbackAction(0);
        }

        Bitmap largeIcon = BitmapFactory.decodeResource(getResources(),
                R.drawable.uow_logo); //replace with your own image

        // Create a new Notification
        NotificationCompat.Builder notificationBuilder = (NotificationCompat.Builder) new NotificationCompat.Builder(this)
                .setShowWhen(false)
                // Set the Notification style
                .setStyle(new NotificationCompat.MediaStyle()
                        // Show our playback controls in the compact notification view.
                        .setShowActionsInCompactView(0))
                // Set the Notification color
                .setColor(getResources().getColor(R.color.colorPrimary))
                // Set the large and small icons
                .setSmallIcon(R.drawable.uow_logo)
                .setLargeIcon(largeIcon)
                // Set Notification content information
                .setContentText("FM Radia")
                .setContentTitle("title abc")
                .setVisibility(NotificationCompat.VISIBILITY_PUBLIC)
                .setAutoCancel(false)
                .setOngoing(true)
                // Add playback actions
                .addAction(notificationAction, "pause", play_pauseAction);


        ((NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE)).notify(NOTIFICATION_ID, notificationBuilder.build());
    }

    private void removeNotification() {
        NotificationManager notificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
        notificationManager.cancel(NOTIFICATION_ID);
    }

    private PendingIntent playbackAction(int actionNumber) {
        Intent playbackAction = new Intent(this, PlayService.class);
        switch (actionNumber) {
            case 0:
                // Play
                playbackAction.setAction(ACTION_PLAY);
                return PendingIntent.getService(this, actionNumber, playbackAction, 0);
            case 1:
                // Pause
                playbackAction.setAction(ACTION_PAUSE);
                return PendingIntent.getService(this, actionNumber, playbackAction, 0);
            default:
                break;
        }
        return null;
    }

    private void handleIncomingActions(Intent playbackAction)
    {
        if (playbackAction == null || playbackAction.getAction() == null) return;

        String actionString = playbackAction.getAction();
        Log.e("actionString",actionString);
        if (actionString.equalsIgnoreCase(ACTION_PLAY))
        {
            //Play the music
        }
        else (actionString.equalsIgnoreCase(ACTION_PAUSE))
        {
            if (mediaPlayer.isPlaying())
                mediaPlayer.stop();
            mediaPlayer.release();
            mediaPlayer = null;
            buildNotification(PlaybackStatus.PAUSED);
            stopSelf();
        }
    }
}