Android 安卓-传感器说明
我正在使用传感器,我在一个网站上找到了这段代码。我理解大部分代码,但不理解float speed=Math.abs.的计算。。有人能解释一下吗?此外,我对最后一个x、最后一个y和最后一个z有点困惑Android 安卓-传感器说明,android,sensors,Android,Sensors,我正在使用传感器,我在一个网站上找到了这段代码。我理解大部分代码,但不理解float speed=Math.abs.的计算。。有人能解释一下吗?此外,我对最后一个x、最后一个y和最后一个z有点困惑 public class MainActivity extends AppCompatActivity implements SensorEventListener { //ACCELEROMETER private Sensor mAccelerometer; private SensorMan
public class MainActivity extends AppCompatActivity implements
SensorEventListener {
//ACCELEROMETER
private Sensor mAccelerometer;
private SensorManager mSensorManager;
private SensorEventListener mSensorListener = this;
private long lastUpdate = 0;
private float last_x, last_y, last_z;
private static final int shakeSensitivity = 600;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);
mAccelerometer = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
mSensorManager.registerListener(this, mAccelerometer, SensorManager.SENSOR_DELAY_NORMAL);
}
@Override
public void onSensorChanged(SensorEvent e) {
float x = e.values[0];
float y = e.values[1];
float z = e.values[2];
//Find current time
long currentTime = System.currentTimeMillis();
//Check if more than 100 milliseconds (0,1 sec) has passed since last invokment of this onSensorChanged method
if ((currentTime - lastUpdate) > 100) {
long diffTime = (currentTime - lastUpdate);
lastUpdate = currentTime;
float speed = Math.abs(x + y + z - last_x - last_y - last_z) / diffTime * 10000;
if (speed > shakeSensitivity) {
//do something
}
last_x = x;
last_y = y;
last_z = z;
}
}
Math.abs返回值的绝对值。如果为-7,则返回7。你不可能真的有负速度,所以它是这样计算的。好的,谢谢。但是你明白最后一部分了吗,用diffTime除以,再乘以10000?为什么是一万?