onSensorChanged() 中的值不会存储在变量中

Question

我有以下函数用于监听加速度计和磁力计值：

  // Storage for Sensor readings

  public float[] mGravity = new float[3];

  public float[] mGeomagnetic = new float[3];

  public void registerSensors(Context context) {

        // First, get an instance of the SensorManager

        SensorManager sMan = (SensorManager) context.getSystemService(Context.SENSOR_SERVICE);

        // Second, get the sensor you're interested in

        Sensor magnetField = sMan.getDefaultSensor(Sensor.TYPE_MAGNETIC_FIELD);

        // Get a reference to the accelerometer

        Sensor accelerometer = sMan.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);

        // Third, implement a SensorEventListener class

        SensorEventListener magnetListener = new SensorEventListener() {

            public void onAccuracyChanged(Sensor sensor, int accuracy) {

                // do things if you're interested in accuracy changes

            }

            public void onSensorChanged(SensorEvent event) {

                mGravity = new float[3];

                //Log.i("LocationUpdater", "magnetometer updated");

                System.arraycopy(event.values, 0, mGravity, 0, 3);

                //Log.i("LocationUpdater", Float.toString(mGravity[0]));

            }

        };

        SensorEventListener accelListener = new SensorEventListener() {

            public void onAccuracyChanged(Sensor sensor, int accuracy) {

                // do things if you're interested in accuracy changes

            }

            public void onSensorChanged(SensorEvent event) {

                mGeomagnetic = new float[3];

                //Log.i("LocationUpdater", "accelerometer updated");

                System.arraycopy(event.values, 0, mGeomagnetic, 0, 3);

            }

        };

但是，从传感器读取的值不会写入数组，所有值都会保留0。这是为什么？

Answer 1

我通过访问这样的变量解决了这个问题：LocationUpdater.mGravity在侦听器内部，这似乎可以解决它。 public void onSensorChanged(SensorEvent event) {                 System.arraycopy(event.values, 0, LocationUpdater.mGravity, 0, 3);  }