安卓培训：Android利用Sensor实现指南针功能

责任编辑：宏鹏来源：武汉北大青鸟鲁广校区时间：04-18

导读：Android利用Sensor实现指南针功能

北大青鸟武汉宏鹏鲁广校区老师解读：Android利用Sensor实现指南针功能

step1:新建一个项目Compass,并将一张指南针图片导入到res/drawable-hdpi目录中

step2:设计应用的UI界面,main.xml

1234567891011121314 <?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="//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>

step3：MainActivity.java

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687 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;/** 传感器管理器 */private SensorManager manager;private SensorListener listener = new SensorListener();@Overridepublic 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);}@Overrideprotected 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();}@Overrideprotected 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;@Overridepublic 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);*/}@Overridepublic void onAccuracyChanged(Sensor sensor, int accuracy) {}}}

step4:AndroidManifest.xml

123456789101112131415161718 <?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="//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>