Android编程之方向传感器用法示例

本文实例讲述了Android编程之方向传感器用法。分享给大家供大家参考，具体如下：

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;
  
  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();
    
    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);
    }
  }
}

更多关于Android相关内容感兴趣的读者可查看本站专题：《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》、《Android资源操作技巧汇总》、《Android文件操作技巧汇总》、《Android开发入门与进阶教程》、《Android编程之activity操作技巧总结》及《Android控件用法总结》

希望本文所述对大家Android程序设计有所帮助。