Android 利用方向传感器实现 指南针
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
[html] view plaincopy
- <span style=”font-size:18px;”><strong><?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></strong></span>
step3:MainActivity.java
[java] view plaincopy
- 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) {
- }
- }
- }
step4:AndroidManifest.xml
[html] view plaincopy
- <span style=”font-size:18px;”><strong><?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></strong></span>