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安卓培训：Android利用Sensor实现指南针功能

时间:2013-05-11 16:18来源:未知作者:中博IT教育点击: 次

step2:设计应用的UI界面,main.xml 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ?xml version= 1.0 encoding= utf-8 ? LinearLayout xmlns:android= http://schemas.android.com/apk/res/android android:orientation= vertical android:layout_width= fill_pare

step2:设计应用的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>

step3：MainActivity.java

		
								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();

								    @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

						<?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>

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