Question

我是Android开发的新手，我需要一些小问题的帮助。我有一个后台服务，它运行我的媒体播放器并与我的PlayerActivity进行通信。到目前为止一切都很好。

我需要安排不同时段的曲目执行。即播放曲目x一分钟而不是播放曲目y 30秒等。

所以我从PlayerActivity调用MyTimer线程，这个线程在特定时间抛出事件，
PlayerActivity捕获Event并调用MediaplayerService next（）方法。我的问题是，如果我调用next（）而没有线程它工作正常，如果我用我得到的线程调用它

 mContext is null, can't getMirrorDisplayStatus!!!

有媒体播放器警告（1,902）我试图通过Handler.post（）和runOnUiThread（）从PlayerActivity运行此线程我得到了同样的错误。

下面是MyTimer Thread的代码。

public class MyTimer implements Runnable {


private Object mPauseLock;
private boolean mPaused;
private boolean mFinished;
private TimeSection section;


public Trainer()
{
    mPauseLock = new Object();
    mPaused = false;
    mFinished = false;
    BusProvider.getInstance().register(this);
}



@Override
public void run()
{
    while (!mFinished)
    {
        TimerManager tm = TimerManager.getInstace();
        this.section = tm.getCurrentTimeSection();
        if(this.section == null)
            mFinished = true;
        else
        {
            tm.inc();
            // produce sectionChangeEvent event
            BusProvider.getInstance().post(produceSectionEvent());
            try
            {
                Thread.sleep((this.section.getTypeDuration() * 1000));
            } catch (InterruptedException e)
            {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        synchronized (mPauseLock)
        {
            while (mPaused)
            {
                try
                {
                    mPauseLock.wait();
                } catch (InterruptedException e)
                {
                }
            }
        }
    }

}

  /**
 * Call this on pause.
 */
public void onPause() {
    synchronized (mPauseLock) {
        mPaused = true;
    }
}

/**
 * Call this on resume.
 */
public void onResume() {
    synchronized (mPauseLock) {
        mPaused = false;
        mPauseLock.notifyAll();
    }
}

@Produce public TimeSectionEvent produceSectionEvent(){
    return new TimeSectionEvent(this.section);
}



}

玩家活动的一些代码：

public class PlayerActivity implements
    IMediaPlayerServiceClient{

private MediaPlayerService mService;

....

/**
 * Binds to the instance of MediaPlayerService. If no instance of
 * MediaPlayerService exists, it first starts a new instance of the service.
 */
public void bindToService()
{
    Intent intent = new Intent(this, MediaPlayerService.class);

    if (MediaPlayerServiceRunning())
    {
        // Bind to LocalService
        bindService(intent, mConnection, Context.BIND_AUTO_CREATE);
    } else
    {
        startService(intent);
        bindService(intent, mConnection, Context.BIND_AUTO_CREATE);


    }

}

.....

/*
* This is how I start the timing thread
*/
private void startTiming()
{
    mTimer = new MyTimer();
    runOnUiThread(mTimer);
//  trainingHandler.post(mTrainer);
}

public void next(TimeSection section)
{
    mService.next(section);
}

/*
* Here I catch the TimeSectionEvent from MyTimer thread
*/
@Subscribe public void onSectionChanged(TimeSectionEvent e)
{
    TimeSection section = e.getSection();
    if(section != null)
         next(section);
}

Answer 1

每个活动都有上下文，所以我认为它与MediaPlayerService的上下文存在问题。

您正在使用bindService（...）将意图绑定到应绑定上下文的MediaPlayerService。

尝试检查当您尝试执行时绑定是否仍然存在＆＃34; mService.next（section）;＆＃34;

Answer 2

问题解决了！

问题在于我是时间线程在UI线程上运行 - ＆gt;调用Thread.sleep也使UI线程处于休眠状态。所以我最终使用IntentService在后台执行计时器线程作业。

public class TimingService extends IntentService{

private Object mPauseLock;
private boolean mPaused;
private boolean mFinished;
private TimeSection section;

public TimingService()
{
    super("TimingService");
    mPauseLock = new Object();
    mPaused = false;
    mFinished = false;
    BusProvider.getInstance().register(this);

}

@Override
protected void onHandleIntent(Intent intent)
{

    while (!mFinished)
{
    TimerManager tm = TimerManager.getInstace();
    this.section = tm.getCurrentTimeSection();
    if(this.section == null)
        mFinished = true;
    else
    {
        tm.inc();
        // produce sectionChangeEvent event
        BusProvider.getInstance().post(produceSectionEvent());
        try
        {
            Thread.sleep((this.section.getTypeDuration() * 1000));
        } catch (InterruptedException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    synchronized (mPauseLock)
    {
        while (mPaused)
        {
            try
            {
                mPauseLock.wait();
            } catch (InterruptedException e)
            {
            }
        }
    }
}

}
  /**
 * Call this on pause.
 */
public void onPause() {
    synchronized (mPauseLock) {
        mPaused = true;
    }
}

/**
 * Call this on resume.
 */
public void onResume() {
    synchronized (mPauseLock) {
        mPaused = false;
        mPauseLock.notifyAll();
    }
}

@Produce public TimeSectionEvent produceSectionEvent(){
return new TimeSectionEvent(this.section);
}

@Subscribe
public void onPauseEvent(PauseEvent e)
{
    this.onPause();
}

@Subscribe
public void onResumeEvent(ResumeEvent e)
{
    this.onResume();
}
}

安排在android中执行mediaplayer

2 个答案: