Android以降のデスクサービスは、本アプリケーションActivityがスタックトップにあるかどうかを判断します

	public boolean isAppOnForeground() {
		List<RunningTaskInfo> tasksInfo = mActivityManager.getRunningTasks(1);
		if (tasksInfo.size() > 0) {
			L.i("top Activity = "
					+ tasksInfo.get(0).topActivity.getPackageName());
			//            
			if (mPackageName.equals(tasksInfo.get(0).topActivity
					.getPackageName())) {
				return true;
			}
		}
		return false;
	}

public void updateServiceNotification(String message) {
		if (!PreferenceUtils.getPrefBoolean(this,
				PreferenceConstants.FOREGROUND, true))
			return;
		String title = PreferenceUtils.getPrefString(this,
				PreferenceConstants.ACCOUNT, "");
		Notification n = new Notification(R.drawable.login_default_avatar,
				title, System.currentTimeMillis());
		n.flags = Notification.FLAG_ONGOING_EVENT | Notification.FLAG_NO_CLEAR;

		Intent notificationIntent = new Intent(this, MainActivity.class);
		notificationIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
		n.contentIntent = PendingIntent.getActivity(this, 0,
				notificationIntent, PendingIntent.FLAG_UPDATE_CURRENT);

		n.setLatestEventInfo(this, title, message, n.contentIntent);
		startForeground(SERVICE_NOTIFICATION, n);
	}

	//               ，              ，
	Runnable monitorStatus = new Runnable() {
		public void run() {
			try {
				L.i("monitorStatus is running... " + mPackageName);
				mMainHandler.removeCallbacks(monitorStatus);
				//              
				if (!isAppOnForeground()) {
					L.i("app run in background...");
					// if (isAuthenticated())//         。
					updateServiceNotification(getString(R.string.run_bg_ticker));
					return;//         ，           
				} else {
					stopForeground(true);
				}
				mMainHandler.postDelayed(monitorStatus, 1000L);
			} catch (Exception e) {
				e.printStackTrace();
				L.i("monitorStatus:"+e.getMessage());
			}
		}
	};