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

step3：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;

	/** 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