以下代码是使用媒体会话(media session)构建音乐通知播放器及其控件的代码。每当我从通知中点击控件时,它就会崩溃,并出现上述错误。请查看下面的代码,并在我出错时进行更正。在下面的代码中,我使用了媒体会话和广播接收器来构建通知。"track" 是包含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());
}