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);    }  }}