backgrounded App peridiocal Handler Wierd行为

Question

我有一个Handler，只需在触发后将“触发”写入文件即可。每5秒触发Handler进行测试。这很奇怪： 当我启动应用程序并且应用程序被预先考虑时，Handler每5秒正常运行一次。如果应用程序背景并且手机已插入笔记本电脑，我可以通过logcat看到一切正常。但是，当我取下电话线并且应用程序背景（未关闭）时，计时器出现问题！

这是我的代码：

public void trigger()
{
    RZTestHandler.removeCallbacks(RZTestTask);
    RZTestHandler.postDelayed(RZTestTask, 5000);
}

private Handler RZTestHandler  = new Handler();

private Runnable RZTestTask = new Runnable() {
    @Override
    public void run() {
        globalVariables.AppLogging("triggered"); //simply writes to file
        Log.d(TAG,"Triggered");
        trigger();
    }
};

从Activity onCreate（）调用：

trigger();

AppLogging方法运行以下代码：

File oFile = new File(filePath);
if (!oFile.exists()) {
    oFile.createNewFile();
}
if (oFile.canWrite()) {
    BufferedWriter oWriter = new BufferedWriter(new FileWriter(new File(filePath),true));
    oWriter.newLine();
    oWriter.write (" ###"+new SimpleDateFormat("dd/MM/yyyy hh:mm:ss a", Locale.ENGLISH).format(new Date())+":Activity:"+sContent +" \n\r"); 
    oWriter.close();
} 

输出

  

19/01/2016 03:26:24 PM：活动：触发

     

19/01/2016 03:26:29 PM：活动：触发

     

19/01/2016 03:26:34 PM：活动：已触发

     

19/01/2016 03:26:39 PM：活动：触发

     

19/01/2016 03:26:45 PM：活动：已触发

     

19/01/2016 03:26:50 PM：活动：触发

     

19/01/2016 03:26:55 PM：活动：已触发

     

19/01/2016 03:27:00 PM：活动：已触发

     

19/01/2016 03:27:05 PM：活动：触发//背景和分离

     

19/01/2016 03:27:14 PM：活动：触发

     

19/01/2016 03:27:27 PM：活动：已触发

     

19/01/2016 03:27:33 PM：活动：已触发

     

19/01/2016 03:27:46 PM：活动：触发//重新附加和前景

     

19/01/2016 03:27:51 PM：活动：触发

     

19/01/2016 03:27:56 PM：活动：已触发

     

19/01/2016 03:28:01 PM：活动：已触发

     

19/01/2016 03:28:06 PM：活动：已触发

     

19/01/2016 03:28:11 PM：活动：已触发

     

19/01/2016 03:28:16 PM：活动：已触发

Answer 1

我按以下方式创建了一个服务，并使用了PowerManager.WakeLock：

 public class PeriodicalTimerService extends Service
    {


        PowerManager.WakeLock wakeLock;
        PowerManager mgr = (PowerManager)MyApplication.getContext().getSystemService(Context.POWER_SERVICE);
        public static Handler RZTestHandler  = new Handler();

        @Override
        public int onStartCommand(Intent intent, int flags, int startId)
        {
            PeriodicalTriggerStarter();
            return START_STICKY;
        }
        private Runnable RZTestTask = new Runnable()
        {
            @Override
            public void run()
            {

                boolean backgrounded = globalVariables.isApplicationSentToBackground();


                if(GlobalVariables.IsSignedIn)
                {
                    if (GlobalVariables.DownloadServiceCanStart)
                    {
                        GlobalVariables.DownloadServiceCanStart=false;
                        StartStopService.StartDownloadService(MyApplication.getContext());
                    }
                    if (wakeLock!=null && wakeLock.isHeld())
                    {
                        wakeLock.release();
                    }
                    Repeater();
                }
                else
                {
                    if (wakeLock != null && wakeLock.isHeld())
                    {
                        wakeLock.release();
                    }
                    stopSelf();
                }
            }
        };

        public void Repeater() {
            wakeLock = mgr.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "RSZWakeLock");
            wakeLock.acquire();

            if (RZTestHandler == null)
            {
                RZTestHandler = new Handler();
            }

            RZTestHandler.removeCallbacksAndMessages(null);
            RZTestHandler.postDelayed(RZTestTask, Long.parseLong(globalVariables.GetSharedStringValue("serviceTimer")));
        }
        public void PeriodicalTriggerStarter()
        {
            if (RZTestHandler == null)
            {
                RZTestHandler = new Handler();
            }

            RZTestHandler.removeCallbacksAndMessages(null);
            RZTestHandler.postAtFrontOfQueue(RZTestTask);
        }
    }