我正在使用AppCompat支持库版本22中的MediaSessionCompat。在Lollipop上，我收到了通知，并且锁屏的背景是专辑封面。一切都很顺利。
而在Pre-Lollipop设备上，锁屏上的音乐控件根本没有显示出来。这很奇怪，我尝试了各种方法，但它并没有显示出来，甚至连背景也没有改变。
我希望有人能解决这个问题。
注意：RemoteControlClient曾在Lollipop和KitKat上工作。
/**
* Initializes the remote control client
*/
private void setupMediaSession() {
/* Activate Audio Manager */
mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
mAudioManager.requestAudioFocus(mAudioFocusListener, AudioManager.STREAM_MUSIC,
AudioManager.AUDIOFOCUS_GAIN);
ComponentName mRemoteControlResponder = new ComponentName(getPackageName(),
MediaButtonReceiver.class.getName());
final Intent mediaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
mediaButtonIntent.setComponent(mRemoteControlResponder);
mMediaSessionCompat = new MediaSessionCompat(getApplication(), "JairSession", mRemoteControlResponder, null);
mMediaSessionCompat.setFlags(MediaSessionCompat.FLAG_HANDLES_MEDIA_BUTTONS | MediaSessionCompat.FLAG_HANDLES_TRANSPORT_CONTROLS);
PlaybackStateCompat playbackStateCompat = new PlaybackStateCompat.Builder()
.setActions(
PlaybackStateCompat.ACTION_SEEK_TO |
PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS |
PlaybackStateCompat.ACTION_SKIP_TO_NEXT |
PlaybackStateCompat.ACTION_PLAY |
PlaybackStateCompat.ACTION_PAUSE |
PlaybackStateCompat.ACTION_STOP
)
.setState(
isPlaying() ? PlaybackStateCompat.STATE_PLAYING : PlaybackStateCompat.STATE_PAUSED,
getCurrentPosition(),
1.0f)
.build();
mMediaSessionCompat.setPlaybackState(playbackStateCompat);
mMediaSessionCompat.setCallback(mMediaSessionCallback);
mMediaSessionCompat.setSessionActivity(retrievePlaybackActions(5));
mMediaSessionCompat.setActive(true);
updateMediaSessionMetaData();
mTransportController = mMediaSessionCompat.getController().getTransportControls();
updateMediaSessionMetaData() 函数：/**
* Updates the lockscreen controls, if enabled.
*/
private void updateMediaSessionMetaData() {
MediaMetadataCompat.Builder builder = new MediaMetadataCompat.Builder();
builder.putString(MediaMetadataCompat.METADATA_KEY_ARTIST, getArtistName());
builder.putString(MediaMetadataCompat.METADATA_KEY_ALBUM, getAlbumName());
builder.putString(MediaMetadataCompat.METADATA_KEY_TITLE, getTrackName());
builder.putLong(MediaMetadataCompat.METADATA_KEY_DURATION, getDuration());
builder.putBitmap(MediaMetadataCompat.METADATA_KEY_ALBUM_ART, MusicUtils.getArtwork(this, getAlbumID(), true));
mMediaSessionCompat.setMetadata(builder.build());
媒体会话回调方法
private final MediaSessionCompat.Callback mMediaSessionCallback = new MediaSessionCompat.Callback() {
@Override
public boolean onMediaButtonEvent(Intent mediaButtonEvent) {
final String intentAction = mediaButtonEvent.getAction();
if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(intentAction)) {
if (PrefUtils.isHeadsetPause(getBaseContext())) {
Log.d(LOG_TAG, "Headset disconnected");
pause();
}
} else if (Intent.ACTION_MEDIA_BUTTON.equals(intentAction)) {
final KeyEvent event = mediaButtonEvent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);
if (event == null) return super.onMediaButtonEvent(mediaButtonEvent);
final int keycode = event.getKeyCode();
final int action = event.getAction();
final long eventTime = event.getEventTime();
if (event.getRepeatCount() == 0 && action == KeyEvent.ACTION_DOWN) {
switch (keycode) {
case KeyEvent.KEYCODE_HEADSETHOOK:
if (eventTime - mLastClickTime < DOUBLE_CLICK) {
playNext(mSongNumber);
mLastClickTime = 0;
} else {
if (isPlaying())
pause();
else resume();
mLastClickTime = eventTime;
}
break;
case KeyEvent.KEYCODE_MEDIA_STOP:
mTransportController.stop();
break;
case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
if (isMediaPlayerActive()) {
if (isPlaying()) mTransportController.pause();
else mTransportController.play();
}
break;
case KeyEvent.KEYCODE_MEDIA_NEXT:
mTransportController.skipToNext();
break;
case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
mTransportController.skipToPrevious();
break;
case KeyEvent.KEYCODE_MEDIA_PAUSE:
mTransportController.pause();
break;
case KeyEvent.KEYCODE_MEDIA_PLAY:
mTransportController.play();
break;
}
}
}
return super.onMediaButtonEvent(mediaButtonEvent);
}
@Override
public void onPlay() {
super.onPlay();
resume();
}
@Override
public void onPause() {
super.onPause();
pause();
}
@Override
public void onSkipToNext() {
super.onSkipToNext();
playNext(mSongNumber);
}
@Override
public void onSkipToPrevious() {
super.onSkipToPrevious();
playPrevious(mSongNumber);
}
@Override
public void onSeekTo(long pos) {
super.onSeekTo(pos);
seekTo(pos);
}
@Override
public void onStop() {
super.onStop();
pause();
commitMusicData();
updatePlayingUI(STOP_ACTION);
stopSelf();
}
};
<!-- Media button receiver -->
<receiver android:name=".receiver.MediaButtonReceiver" >
<intent-filter>
<action android:name="android.intent.action.MEDIA_BUTTON" />
<action android:name="android.media.AUDIO_BECOMING_NOISY" />
</intent-filter>
</receiver>
我已经尝试了几周来解决这个问题，但一直没有成功，非常需要帮助。
编辑：有关MediaSessionCompat的教程或示例也可以。