Android编程之方向传感器用法示例

/**
* 传感器指针Demo
*
* @description：
* @author ldm
* @date 2016-4-25 下午5:29:18
*/
public class SensorHandActivity extends GraphicsActivity {
// 传感器管理对象
private SensorManager mSensorManager;
// 传感器类
private Sensor mSensor;
// 自定义绘制指针View
private MyCompassView mView;
/**
* 方向传感器检测到的感应值 values[0]: Azimuth(方位)，地磁北方向与y轴的角度，围绕z轴旋转(0到359)。0=North,
* 90=East, 180=South, 270=West values[1]: Pitch(俯仰),围绕X轴旋转(-180 to 180),
* 当Z轴向Y轴运动时是正值 values[2]: Roll(滚)，围绕Y轴旋转(-90 to 90)，当X轴向Z轴运动时是正值
*/
private float[] mValues;
// 传感监听
private final SensorEventListener mSensorListener = new SensorEventListener() {
public void onSensorChanged(SensorEvent event) {
mValues = event.values;
if (mView != null) {
mView.invalidate();
}
}
public void onAccuracyChanged(Sensor sensor, int accuracy) {
}
};
@SuppressWarnings("deprecation")
@Override
protected void onCreate(Bundle icicle) {
super.onCreate(icicle);
mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
mView = new MyCompassView(this);
setContentView(mView);
}
@Override
protected void onResume() {
super.onResume();
/**
* 在onResume方法中注册传感器监听 事件
* 第一个参数：监听Sensor事件，第二个参数是Sensor目标种类的值，第三个参数是延迟时间的精度密度。延迟时间的精密度参数 参数
* 延迟时间 SensorManager.SENSOR_DELAY_FASTEST 0ms
* SensorManager.SENSOR_DELAY_GAME 20ms SensorManager.SENSOR_DELAY_UI
* 60ms SensorManager.SENSOR_DELAY_NORMAL 200ms
*/
mSensorManager.registerListener(mSensorListener, mSensor,
SensorManager.SENSOR_DELAY_GAME);
}
@Override
protected void onStop() {
// 在onStop方法中取消注册监听
mSensorManager.unregisterListener(mSensorListener);
super.onStop();
}
private class MyCompassView extends View {
// 定义画笔Paint
private Paint mPaint;
// 定义绘制指针的路径Path
private Path mPath;
public MyCompassView(Context context) {
super(context);
initPaintAndPath();
}
private void initPaintAndPath() {
// 初始化画笔
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setColor(Color.BLACK);
mPaint.setStyle(Paint.Style.FILL);
// 初始化绘制路径
mPath = new Path();
mPath.moveTo(0, -50);// 移动到指点点
mPath.lineTo(-20, 60);// 用线条连接到指定点
mPath.lineTo(0, 50);
mPath.lineTo(20, 60);
mPath.close();// 关闭路径
}
@Override
protected void onDraw(Canvas canvas) {
// 设置画面背景
canvas.drawColor(Color.WHITE);
int w = canvas.getWidth();
int h = canvas.getHeight();
int cx = w / 2;
int cy = h / 2;
canvas.translate(cx, cy);// 移动画面，把指针放到中央
if (mValues != null) {
canvas.rotate(-mValues[0]);
}
canvas.drawPath(mPath, mPaint);
}
}
}