无法设置锁屏专辑封面

Question

我正在制作音频播放器。我为此目的实现了后台服务。现在，我正在尝试使用mediasession将音频专辑封面显示为锁屏壁纸。我已成功实现了锁屏播放控件和通知，但我无法将专辑封面显示为锁屏壁纸。

我正在使用的代码：

   private void initMediaSession() throws RemoteException {
    if (mediaSessionManager != null) return; //mediaSessionManager exists

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
        mediaSessionManager = (MediaSessionManager) getSystemService(Context.MEDIA_SESSION_SERVICE);
    }
    // Create a new MediaSession
    mediaSession = new MediaSessionCompat(this, "AudioPlayer");
    //Get MediaSessions transport controls
    transportControls = mediaSession.getController().getTransportControls();
    //set MediaSession -> ready to receive media commands
    mediaSession.setActive(true);
    //indicate that the MediaSession handles transport control commands
    // through its MediaSessionCompat.Callback.
    mediaSession.setFlags(MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS|MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS);

    //Set mediaSession's MetaData
    updateMetaData();

    mediaSession.setCallback(new MediaSessionCompat.Callback() {
        @Override
        public void onPlay() {
            super.onPlay();

            resumeMedia();
        }

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

            pauseMedia();
        }

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

            skipToNext();
        }

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

            skipToPrevious();
        }
    });


}



 private void updateMetaData() {

    // Update the current metadata
    metaDataBuilder = new MediaMetadataCompat.Builder();
 //   Bitmap bitmap =BitmapFactory.decodeResource(getResources(), R.drawable.placeholder);
    metaDataBuilder.putString(MediaMetadataCompat.METADATA_KEY_ARTIST, songInfoModelService.getArtistName())
            .putString(MediaMetadataCompat.METADATA_KEY_TITLE, songInfoModelService.getSongName());

    Glide.with(this).asBitmap().load(songInfoModelService.getAlbumIDArtwork()).into(new SimpleTarget<Bitmap>() {
        @Override
        public void onResourceReady(@NonNull Bitmap resource, Transition<? super Bitmap> transition) {

            metaDataBuilder.putBitmap(MediaMetadataCompat.METADATA_KEY_ART,resource);
            metaDataBuilder.putBitmap(MediaMetadataCompat.METADATA_KEY_ALBUM_ART, resource);


            mediaSession.setMetadata(metaDataBuilder.build());

        }
    });


}`