Question

在我的应用程序中，我有一个音频播放器Activity，它只显示当前歌曲标题和专辑封面以及MediaController。我还有Service实现MediaController.MediaPlayerControl并使用MediaPlayer进行播放。

一般来说一切正常 - Activity绑定到Service并设置MediaController来控制MediaPlayer。

当屏幕上显示MediaController时，开始播放新歌时会出现问题，但仅。如果它被隐藏，或者即使我使用BACK退出Activity并返回主屏幕，“播放列表”也是如此。处理没有问题。但是，如果MediaContoller可见，则播放器会静默死亡，搜索/进度条显示开始和结束时间为466：36：07并且logcat显示...

attempt to call getDuration without a valid mediaplayer

我没有在logcat中获得未处理的异常堆栈跟踪 - 只是该消息而MediaPlayer只是停止播放。我已经用Google搜索了这个错误并获得了近3000次点击（其中大部分都是关于SO的问题）但是我找不到与我匹配的情况。

相关的Activity代码......

public class AudioPlayerActivity extends Activity
    implements OnKeyListener {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.audio_player);

        // Find views here

        controller = new MyMediaController(this);
        controller.setAnchorView(ll);
        controller.setOnKeyListener(this);
    }

    @Override
    protected void onResume() {
        super.onResume();

        mBound = bindService(new Intent(this, MusicPlayerService.class), mConnection, Context.BIND_AUTO_CREATE);

        try {
            getCurrentItem();
            mediaFilename = currentItem.getTrackName();
            coverArtPath = currentItem.getMediaArtUrl();
            updateTrackDetails();
            Intent playerServiceIntent = new Intent(this, MusicPlayerService.class);
            startService(playerServiceIntent);
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void showMediaController() {
        // Called by onTouchEvent(...)` when the screen is touched
        if (mBound) {
            controller.setMediaPlayer(mService);
            controller.setEnabled(true);
            controller.show(0);
        }
    }
}

Service包含以下代码......

public class NDroidTEMusicPlayerService extends Service
    implements MediaPlayer.OnPreparedListener,
        MediaPlayer.OnCompletionListener,
        MediaPlayer.OnErrorListener,
        AudioManager.OnAudioFocusChangeListener,
        MediaPlayerControl {

    private void setupMediaPlayer() {
        ...
        try {
            mMediaPlayer.setDataSource(trackUrl);
            mMediaPlayer.prepareAsync();
        } catch (IllegalArgumentException e) {
            e.printStackTrace();
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (IllegalStateException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    @Override
    public void onCompletion(MediaPlayer mp) {
        stop();
        mp.reset();
        currentItem = playList.getNextItem(isRepeating);
        Intent i = new Intent(MYAPP.ACTION_MYAPP_UPDATE_PLAY_VIEW);
        i.putExtra("current_item", currentItem);
        sendBroadcast(i);
        setupMediaPlayer();
    }

    @Override
    public int getDuration() {
        int duration = 0;
        if (mMediaPlayer != null) 
            duration = mMediaPlayer.getDuration();
        return duration;
    }
}

MediaController与ServicePlayer in Service getDuration错误

0 个答案: