Android开发中方向传感器定义与用法详解【附指南针实现方法】

private SensorManager sensorManager;
private MySensorEventListener mySensorEventListener;
mySensorEventListener= new MySensorEventListener();//这个监听器当然是我们自己定义的，在方向感应器感应到手机方向有变化的时候，我们可以采取相应的操作，这里紧紧是将x,y,z的值打印出来
private final class MySensorEventListener implements SensorEventListener{
@Override
//可以得到传感器实时测量出来的变化值
public void onSensorChanged(SensorEvent event) {
//方向传感器
if(event.sensor.getType()==Sensor.TYPE_ORIENTATION){
//x表示手机指向的方位，0表示北,90表示东，180表示南，270表示西
float x = event.values[SensorManager.DATA_X];
float y = event.values[SensorManager.DATA_Y];
float z = event.values[SensorManager.DATA_Z];
//tv_orientation是界面上的一个TextView标签，不再赘述
tv_orientation.setText("Orientation:"+x+","+y+","+z);
}
}

protected void onResume() {
  Sensor sensor_orientation=sensorManager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
  sensorManager.registerListener(mySensorEventListener,sensor_orientation, SensorManager.SENSOR_DELAY_UI);
super.onResume();
}

protected void onPause() {
//注销所有传感器的监听
sensorManager.unregisterListener(mySensorEventListener);
super.onPause();
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  android:gravity="center"
  >
<ImageView
  android:layout_width="wrap_content"
  android:layout_height="wrap_content"
  android:src="@drawable/compass"
  android:id="@+id/imageView"
  />
</LinearLayout>

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.view.animation.Animation;
import android.view.animation.RotateAnimation;
import android.widget.ImageView;
public class MainActivity extends Activity {
  private ImageView imageView;
  /** 传感器管理器 */
  private SensorManager manager;
  private SensorListener listener = new SensorListener();
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    imageView = (ImageView) this.findViewById(R.id.imageView);
    imageView.setKeepScreenOn(true);//屏幕高亮
    //获取系统服务（SENSOR_SERVICE)返回一个SensorManager 对象
    manager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
  }
  @Override
  protected void onResume() {
    /**
     * 获取方向传感器
     * 通过SensorManager对象获取相应的Sensor类型的对象
     */
    Sensor sensor = manager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
    //应用在前台时候注册监听器
    manager.registerListener(listener, sensor,
        SensorManager.SENSOR_DELAY_GAME);
    super.onResume();
  }
  @Override
  protected void onPause() {
    //应用不在前台时候销毁掉监听器
    manager.unregisterListener(listener);
    super.onPause();
  }
  private final class SensorListener implements SensorEventListener {
    private float predegree = 0;
    @Override
    public void onSensorChanged(SensorEvent event) {
      /**
       * values[0]: x-axis 方向加速度
      　　 values[1]: y-axis 方向加速度
      　　 values[2]: z-axis 方向加速度
       */
      float degree = event.values[0];// 存放了方向值
      /**动画效果*/
      RotateAnimation animation = new RotateAnimation(predegree, degree,
          Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF,0.5f);
      animation.setDuration(200);
      imageView.startAnimation(animation);
      predegree=-degree;
      /**
      float x=event.values[SensorManager.DATA_X];
      float y=event.values[SensorManager.DATA_Y];
      float z=event.values[SensorManager.DATA_Z];
      Log.i("XYZ", "x="+(int)x+",y="+(int)y+",z="+(int)z);
      */
    }
    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
    }
  }
}

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
   package="cn.roco.sensor"
   android:versionCode="1"
   android:versionName="1.0">
  <uses-sdk android:minSdkVersion="8" />
  <application android:icon="@drawable/icon" android:label="@string/app_name">
    <activity android:name="MainActivity"
         android:label="@string/app_name">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
  </application>
</manifest>