尝试调用接口方法'；android.media.session.ISessionController android.media.session.ISession.getController（）'；关于空对象

下面的代码是用于带有使用媒体会话的控件的音乐通知播放器。每当我单击通知中的控件时，它就会崩溃，并出现上述错误。请查看下面的代码，如果我错了请纠正我。在下面的代码中，我使用了媒体会话和广播接收器来生成通知。“track”是我所有歌曲数据的模型类

   try {
                if (track.getImage() == null) {
                    track.setImage(BitmapFactory.decodeResource(context.getResources(),
                            R.mipmap.ic_launcher));
                }
    
    
                NotificationManagerCompat notificationManagerCompat = NotificationManagerCompat.from(context);
                MediaSessionCompat mediaSessionCompat = new MediaSessionCompat(context, "tag");
                mediaSessionCompat.setMetadata(
                        new MediaMetadataCompat.Builder()
                                .putString(MediaMetadata.METADATA_KEY_TITLE, track.getTitle())
                                .putString(MediaMetadata.METADATA_KEY_ARTIST, track.getArtist())
                                .putBitmap(MediaMetadata.METADATA_KEY_ALBUM_ART, track.getImage())
                                .putString(MediaMetadata.METADATA_KEY_ALBUM, track.getAlbum())
                                .build()
                );
                mediaSessionCompat.setFlags(
                        MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS |
                                MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
    
                PlaybackStateCompat.Builder stateBuilder = new PlaybackStateCompat.Builder();
    
                stateBuilder.setActiveQueueItemId(MediaSession.QueueItem.UNKNOWN_ID);
    
                long actions = PlaybackStateCompat.ACTION_PLAY_PAUSE | PlaybackStateCompat.ACTION_STOP | PlaybackStateCompat.ACTION_SKIP_TO_NEXT | PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS;
                stateBuilder.setActions(actions);
                if (isPlaying) {
                    stateBuilder.setState(PlaybackStateCompat.STATE_PLAYING, 0, 1.0f);
                    mediaSessionCompat.setActive(true);
    
                } else {
                    stateBuilder.setState(PlaybackStateCompat.STATE_PAUSED, 0, 1.0f);
                    mediaSessionCompat.setActive(true);
    
    
                }
                mediaSessionCompat.setPlaybackState(stateBuilder.build());
                Bitmap icon = track.getImage();
    
    
                PendingIntent pendingIntentPrevious;
                int drw_previous;
    
    //                pendingIntentPrevious = null;
    //                drw_previous = 0;
                Intent intentPrevious = new Intent(context, NotificationActionService.class)
                        .setAction(ACTION_PREVIUOS);
                pendingIntentPrevious = PendingIntent.getBroadcast(context, 0,
                        intentPrevious, PendingIntent.FLAG_UPDATE_CURRENT);
                drw_previous = R.drawable.ic_back;
                Intent intentPlay = new Intent(context, NotificationActionService.class)
                        .setAction(ACTION_PLAY);
                PendingIntent pendingIntentPlay = PendingIntent.getBroadcast(context, 0,
                        intentPlay, PendingIntent.FLAG_UPDATE_CURRENT);
    
                PendingIntent pendingIntentNext;
                int drw_next;
    //                pendingIntentNext = null;
    //                drw_next = 0;
                Intent intentNext = new Intent(context, NotificationActionService.class)
                        .setAction(ACTION_NEXT);
                pendingIntentNext = PendingIntent.getBroadcast(context, 0,
                        intentNext, PendingIntent.FLAG_UPDATE_CURRENT);
                drw_next = R.drawable.ic_next;
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                    notification = new NotificationCompat.Builder(context, CHANNEL_ID)
                            .setSmallIcon(R.drawable.logo)
                            .setContentTitle(track.getTitle())
                            .setContentText(track.getArtist())
                            .setLargeIcon(icon)
                            .setAutoCancel(isPlaying ? false : true)
                            .setOngoing(isPlaying ? true : false)
                            .setWhen(0)
                            .setNotificationSilent()
                            .setSound(null)
                            .addAction(drw_previous, "Previous", pendingIntentPrevious)
                            .addAction(playbutton, "Play", pendingIntentPlay)
                            .addAction(drw_next, "Next", pendingIntentNext)
                            .setStyle(new androidx.media.app.NotificationCompat.MediaStyle()
                                    .setShowActionsInCompactView(0, 1, 2)
                                    .setMediaSession(mediaSessionCompat.getSessionToken()))
                            .setPriority(NotificationCompat.PRIORITY_LOW)
                            .build();
    
                } else {
                    notification = new NotificationCompat.Builder(context, CHANNEL_ID)
                            .setSmallIcon(R.drawable.logo)
                            .setContentTitle(track.getTitle())
                            .setContentText(track.getArtist())
                            .setLargeIcon(icon)
                            .setAutoCancel(true)
                            .setOngoing(false)
                            .setWhen(0)
                            .setNotificationSilent()
                            .setSound(null)
                            .addAction(drw_previous, "Previous", pendingIntentPrevious)
                            .addAction(playbutton, "Play", pendingIntentPlay)
                            .addAction(drw_next, "Next", pendingIntentNext)
                            .setStyle(new androidx.media.app.NotificationCompat.MediaStyle()
                                    .setShowActionsInCompactView(0, 1, 2)
                                    .setMediaSession(mediaSessionCompat.getSessionToken()))
                            .setPriority(NotificationCompat.PRIORITY_LOW)
                            .build();
    
                }
    
                notificationManagerCompat.notify(1, notification);
            } catch (Exception e) {
                Log.e("media sesison", e.getLocalizedMessage());
            }

   

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这回答了你的问题吗@frankenapps否，我正在寻找具有播放暂停控制并通过应用内通知生成器处理的媒体播放通知。