触发onPlaybackStateChanged我有这样的媒体播放器和其他一切工作正常,我开始播放歌曲,它就会通过2个状态,最后一个是PlaybackStateCompat.STATE_PLAYING
SeekTo不MediaControllerCompat
因此,我们可以说,回调被注册。问题是每当我触发SeekBar侦听器,方法seekTo
不会触发onPlaybackStateChanged
,因为这没有发生,我不能更新SeekBar到其新的进展。这只涉及UI。在修改SeekBar进度后,音乐实际上是从进度播放。更重要的是,trackDurationTextView也不会更新。当我在搜索栏上拖动我的拇指时,它会改变它的值,但是一旦我释放它,它会转到它的初始进度,与搜索栏相同。
这里是回调注册的地方。
@Override
public void onServiceConnected(ComponentName componentName, IBinder service) {
if (service instanceof MediaPlayerService.ServiceBinder) {
try {
mediaController = new MediaControllerCompat(this, ((MediaPlayerService.ServiceBinder) service).getService().getMediaSessionToken());
} catch (RemoteException e) {
e.printStackTrace();
}
mediaController.registerCallback(mMediaControllerCallback);
}
}
这是回调如何初始化:
private MediaControllerCompat.Callback mMediaControllerCallback = new MediaControllerCompat.Callback() {
@Override
public void onPlaybackStateChanged(@NonNull PlaybackStateCompat state) {
updatePlaybackState(state);
}
@Override
public void onMetadataChanged(MediaMetadataCompat metadata) {
if (metadata != null) {
updateMediaDescription(metadata.getDescription());
updateDuration(metadata);
}
}
};
这是OnSeekBarChangeListener
trackSeekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
trackDurationTextView.setText(DateUtils.formatElapsedTime(progress/1000));
}
@Override
public void onStartTrackingTouch(SeekBar seekBar) {
stopSeekbarUpdate();
}
@Override
public void onStopTrackingTouch(SeekBar seekBar) {
//TODO: look here! the seek bar position is not kept when the user slides it!
mediaController.getTransportControls().seekTo(seekBar.getProgress());
scheduleSeekBarUpdate();
}
});
private void updateProgress() {
if (mLastPlaybackState == null) {
return;
}
long currentPosition = mLastPlaybackState.getPosition();
if (mLastPlaybackState.getState() != PlaybackStateCompat.STATE_PAUSED) {
// Calculate the elapsed time between the last position update and now and unless
// paused, we can assume (delta * speed) + current position is approximately the
// latest position. This ensure that we do not repeatedly call the getPlaybackState()
// on MediaControllerCompat.
long timeDelta = SystemClock.elapsedRealtime() -
mLastPlaybackState.getLastPositionUpdateTime();
currentPosition += (int) timeDelta * mLastPlaybackState.getPlaybackSpeed();
}
trackSeekBar.setProgress((int) currentPosition);
}
这是mLastPlayBackState.getPosition应搜索栏后返回新值的地方被更新,但它总是返回0,因为onPlaybackStateChanged永远不会被调用。任何想法为什么?
你能找到解决方案吗?我正在面对一个类似的问题,即seekTo开始播放但状态未更新。 – mobiledev
“Callback.onSeekTo”中的代码是什么?你在哪里调用'mediaSession.setState()'? – ianhanniballake