android-如何實時監視設備的方向？

Question

我要監控的Android設備只是在定向realtime （我的意思是不斷並提取新的方向盡可能快）。 我將ACCELEROMETER和MAGNETIC_FIELD結合使用，並為兩個拖曳傳感器發生的變化提供了拖車監聽器。 現在在哪里放置這兩行代碼以獲取方向？

SensorManager.getRotationMatrix(R, null, aValues, mValues);
SensorManager.getOrientation(R, values);

我制作了一個后台Thread並將該代碼放入無限for loop ...這是一個好的實現嗎？

    ExecutorService executor = Executors.newCachedThreadPool();
    executor.execute(new Runnable() {

        @Override
        public void run() {
            for (;;) {
                SensorManager.getRotationMatrix(R, null, aValues, mValues);
                SensorManager.getOrientation(R, values);
                      }
                          }
                                    }

Answer 1

您應該使用SensorEventListener

private final SensorEventListener mSensorListener = new SensorEventListener() {

    public void onSensorChanged(SensorEvent se) {
      float x = se.values[0];
      float y = se.values[1];
      float z = se.values[2];
      mAccelLast = mAccelCurrent;
      mAccelCurrent = (float) Math.sqrt((double) (x*x + y*y + z*z));
      float delta = mAccelCurrent - mAccelLast;
      mAccel = mAccel * 0.9f + delta; // perform low-cut filter
    }

    public void onAccuracyChanged(Sensor sensor, int accuracy) {
    }
};

在您的活動中，您必須導入：

private SensorManager mSensorManager;
private float mAccel; // acceleration apart from gravity
private float mAccelCurrent; // current acceleration including gravity
private float mAccelLast; // last acceleration including gravity

並初始化：

mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
mSensorManager.registerListener(mSensorListener, mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER), SensorManager.SENSOR_DELAY_NORMAL);
mAccel = 0.00f;
mAccelCurrent = SensorManager.GRAVITY_EARTH;
mAccelLast = SensorManager.GRAVITY_EARTH;