Android Simple step using directional sensor to implement compass

Step 1: Create a new project compass and import a compass picture into the res/drawable-hdpi directory

Step 2: Design the UI interface for the application, 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>

Step 3:mainactivity.java

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;  
      
    /** Sensor Manager */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);//screen highlighting//Get system Services (Sensor_service) returns a Sensormanager object manager = (sensorm Anager) GetsystemservIce (Context.sensor_service); @Override protected void Onresume () {/** * get direction sensor * through Sensormanager object  
        Gets the corresponding Sensor type of object/Sensor Sensor = Manager.getdefaultsensor (sensor.type_orientation);  
        Application in the foreground when registering listener manager.registerlistener (listener, sensor, sensormanager.sensor_delay_game);  
    Super.onresume (); @Override protected void OnPause () {//application is not destroyed at the front of the listener Manager.unregisterlistener (li  
        Stener);  
    Super.onpause (); Private Final class Sensorlistener implements Sensoreventlistener {private float Predegre  
      
        e = 0; @Override public void onsensorchanged (Sensorevent event) {/** * Values[0]: X-axis direction Acceleration Values[1]: Y-axis direction acceleration values[2]: Z-axis direction acceleration/float deg REE = event.values[0];//Store the directional value/** animation effect * * 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) { }  
      
    }  
}

Step 4: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.intent.category.LAUNCHER"/>  
            </intent-filter>  
        </activity>  
      
    </ Application>  
</manifest>