指南针

 1 public class SensorZhinan extends Activity implements SensorEventListener{
 2 
 3     private ImageView point;
 4     private SensorManager sensor;
 5     private float currentDegree=0;
 6     @Override
 7     protected void onCreate(Bundle savedInstanceState) {
 8         // TODO Auto-generated method stub
 9         super.onCreate(savedInstanceState);
10         setContentView(R.layout.activity_zhinanzheng);
11         point=(ImageView) findViewById(R.id.point_image);
12         sensor=(SensorManager) getSystemService(Context.SENSOR_SERVICE);
13         
14     }
15     
16     @Override
17     protected void onResume() {
18         // TODO Auto-generated method stub
19         super.onResume();
　　　　　　　　//注册方向传感器
20         sensor.registerListener(this, sensor.getDefaultSensor(Sensor.TYPE_ORIENTATION), SensorManager.SENSOR_DELAY_GAME);
21         
22     }
23     
24     @Override
25     protected void onPause() {
26         // TODO Auto-generated method stub
27         super.onPause();
28         sensor.unregisterListener(this);
29     }
30     @Override
31     protected void onStop() {
32         // TODO Auto-generated method stub
33         super.onStop();
34         sensor.unregisterListener(this);
35     }
36     
37     
38     @Override
39     public void onSensorChanged(SensorEvent event) {
40         // TODO Auto-generated method stub
41         float degree=event.values[0];
42         
43         RotateAnimation ra=new RotateAnimation(currentDegree, -degree, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);
44         ra.setDuration(200);
45         point.startAnimation(ra);
46         currentDegree=-degree;
47     }
48     @Override
49     public void onAccuracyChanged(Sensor sensor, int accuracy) {
50         // TODO Auto-generated method stub
51         
52     }
53     
54     @Override
55     protected void onDestroy() {
56         // TODO Auto-generated method stub
57         super.onDestroy();
58         sensor.unregisterListener(this);
59         finish();
60     }
61 }