停止服务后如何从传感器注销监听器？

Question

我正在创建一个应用程序，该应用程序在按下“开始”按钮时启动服务，并在按下“停止”按钮时停止服务。在服务中，我为传感器 ACCELEROMETER 注册了一个侦听器，以便获得 x、y、z 轴的加速度计值。但是当我停止我的应用程序并从传感器注销侦听器时，即使这样我也得到了我的加速度计值。

代码如下：

// Service
public class Accel extends Service
{
    private static Context CONTEXT; 
    private static Sensor sensor;
    private static SensorManager sensorManager;
    private static boolean running = false;

    @Override
    public void onCreate()
    {
    }

    // code to execute when the service is shutting down
    @Override
    public void onDestroy()
    {
        if (isListening())
            stopListening();
    }

    // code to execute when the service is starting up 
    @Override
    public void onStart(Intent intent, int startid)
    {
        CONTEXT = this;
        startListening(this);
    }

    public static Context getContext()
    {
        return CONTEXT;
    }

    // Returns true if the manager is listening to orientation changes
    public static boolean isListening()
    {
        return running;
    }

    //Unregisters listeners
    public static void stopListening()
    {
        running = false;
        sensorManager.unregisterListener(sensorEventListener, sensor);
    }

    /**
     * Registers a listener and start listening
     * @param accelerometerListener
     *             callback for accelerometer events
     */
    public static void startListening(AccelerometerListener accelerometerListener)
    {
        sensorManager = (SensorManager) getContext().getSystemService(Context.SENSOR_SERVICE);
        List<Sensor> sensors = sensorManager.getSensorList(Sensor.TYPE_ACCELEROMETER);
        if (sensors.size() > 0)
        {
            sensor = sensors.get(0);
            running = sensorManager.registerListener(sensorEventListener, sensor, SensorManager.SENSOR_DELAY_GAME);
            listener = accelerometerListener;
        }
    }

    /**
     * The listener that listen to events from the accelerometer listener
     */
    private static SensorEventListener sensorEventListener = 
    new SensorEventListener()
    {
    public void onAccuracyChanged(Sensor sensor, int accuracy) {}
    public void onSensorChanged(SensorEvent event)
    {
                // the code to perform on sensor change
    }
};

}

谁能帮帮我？

Answer 1

onDestroy() 可能不会立即被您应用上的操作系统调用。将您的stopListening() 调用放入onPause()，并将startListening() 放入您的onResume() 函数中。这样，您就可以保证应用在传感器上注册和取消注册。