Android利用Sensor實現指南針功能

step1:新建一個項目Compass,并將一張指南針圖片導入到res/drawable-hdpi目錄中

step2:設計應用的UI界面,main.xml

<?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>

package cn.roco.sensor;

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;

    /** 傳感器管理器 */
    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
        //獲取系統服務（SENSOR_SERVICE)返回一個SensorManager 對象
        manager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    }

    @Override
    protected void onResume() {
        /**
         *  獲取方向傳感器
         *  通過SensorManager對象獲取相應的Sensor類型的對象
         */
        Sensor sensor = manager.getDefaultSensor(Sensor.TYPE_ORIENTATION);
        //應用在前臺時候注冊監聽器
        manager.registerListener(listener, sensor,
                SensorManager.SENSOR_DELAY_GAME);
        super.onResume();
    }

    @Override
    protected void onPause() {
        //應用不在前臺時候銷毀掉監聽器
        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
            /**動畫效果*/
            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>

step5:部署應用到真機環境中  就可以查看運行的效果啦

 來自：http://blog.csdn.net/qq446282412/article/details/8801204