android - 手机休眠时播放声音

Question

我正在编写一项以随机间隔提醒用户的服务。该服务由 Activity 启动，并作为服务在后台运行。

我面临的挑战是，当用户将手机置于 sleep 状态(黑屏)时，在某些情况下根本不会播放声音。时间已用完，但声音既不会按时播放，也不会在用户唤醒手机时播放。

这是一些代码:

/**
 * Starts a new thread which is checking every seconds how much time has
 * elapsed and if the point of time has come to play the sound.
 * Once the time has come, it gets the next ring time and continues
 * until it is shut down by the user
 */
private void runCheck() {
    Log.i(tag, "starting runCheck");

    Thread thread = new Thread() {
        public void run() {

            Log.i(tag, "starting LogoTimerThread");
            while (vRunningFlag) {

                try {

                    // update the notification
                    makeNotification();

                    Log.v(tag,
                            "Next Ring in : ["
                                    + helper.TimeCalculator
                                            .duration2_hh_MM_SS((vTimerNextRing - System
                                                    .currentTimeMillis()) / 1000)
                                    + " sec.]");

                    // check if time has run out
                    if (vTimerNextRing < System.currentTimeMillis()) {
                        // reset the timer
                        setNextRingTime();
                        // update the screen
                        makeNotification();
                        // play the sound
                        playLTimerSound();
                    }

                    sleep(1000);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }

            }
            Log.i(tag, "finished LogoTimerThread");
        }
    };

    thread.start();
}

整个服务作为设置为前台的远程服务运行，因此通知提醒用户该服务，他可以通过这种方式停止它。

一旦我注释掉 playLTimerSound() ，计时器只会倒计时。不知何故，线程通过播放声音而停止。

这也是该功能:

public void playLTimerSound() {
    Log.i(tag, "playLogoTimerSound - volume:" + vVolume);
    MediaPlayer mp = MediaPlayer.create(this, R.raw.enterprise);
    mp.setVolume(2.0f, 2.0f);
    mp.start();
    mp.setOnCompletionListener(new OnCompletionListener() {
        @Override
        public void onCompletion(MediaPlayer mp) {
            // TODO Auto-generated method stub
            mp.release();
        }
    });
}

Answer 1

在您的场景中无法获取 SCREEN_DIM_WAKE_LOCK 吗？

@Override
 protected void onCreate(Bundle icicle) {
     super.onCreate(icicle);




PowerManager pm = (PowerManager) getSystemService(Context.POWER_SERVICE);
wl = pm.newWakeLock(PowerManager.SCREEN_DIM_WAKE_LOCK, "App");
wl.acquire();

}