Android重力传感器实现滚台球

package cn.itcast.accelerometer;import cn.itcast.accelerometer.view.BallView;import android.app.Activity;import android.hardware.Sensor;import android.hardware.SensorEvent;import android.hardware.SensorEventListener;import android.hardware.SensorManager;import android.os.Bundle;import android.view.View;import android.widget.TextView;/** * 利用重力加速度传感器实现滚桌球游戏 * 参考资料： * 1> http://ophonesdn.com/article/show/183 * 2> 重力加速度原理学习资料 http://www.riameeting.com/node/538 * 由于重力加速度传感器需要在真机才能测试，为了能在模拟器中测试，可以按下面文章搭建测试环境： * http://www.xiaojiayi.com/ * */public class AccelerometerActivity extends Activity {private static final float MAX_ACCELEROMETER = 9.81f;private SensorManager sensorManager; private BallView ball; private boolean success = false; private boolean init = false; private int container_width = 0;private int container_height = 0;private int ball_width = 0;private int ball_height = 0;private TextView prompt;    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);        //获取感应器管理器        sensorManager = (SensorManager) getSystemService(SENSOR_SERVICE);        prompt = (TextView) findViewById(R.id.ball_prompt);       }@Overridepublic void onWindowFocusChanged(boolean hasFocus) {//ball_container控件显示出来后才能获取其宽和高，所以在此方法得到其宽高super.onWindowFocusChanged(hasFocus);if(hasFocus && !init){View container = findViewById(R.id.ball_container);    container_width = container.getWidth();    container_height = container.getHeight();    ball = (BallView) findViewById(R.id.ball);    ball_width = ball.getWidth();    ball_height = ball.getHeight();    moveTo(0f, 0f);    init = true;}}@Overrideprotected void onResume() {Sensor sensor = sensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);//获取重力加速度感应器success = sensorManager.registerListener(listener, sensor, SensorManager.SENSOR_DELAY_GAME);//注册listener，第三个参数是检测的精确度 super.onResume();}         @Overrideprotected void onPause() {    if(success) sensorManager.unregisterListener(listener);super.onPause();}private SensorEventListener listener = new SensorEventListener() {@Overridepublic void onSensorChanged(SensorEvent event) {if (!init) return ;float x = event.values[SensorManager.DATA_X];              float y = event.values[SensorManager.DATA_Y];              float z = event.values[SensorManager.DATA_Z];          prompt.setText("Sensor: " + x + ", " + y + ", " + z);         //当重力x,y为0时，球处于中心位置，以y为轴心（固定不动），转动手机，x会在（0-9.81)之间变化，负号代表方向        moveTo(-x, y);//x方向取反}@Overridepublic void onAccuracyChanged(Sensor sensor, int accuracy) {}};private void moveTo(float x, float y) {        int max_x = (container_width - ball_width) / 2;//在x轴可移动的最大值        int max_y = (container_height - ball_height) / 2;//在y轴可移动的最大值        //手机沿x、y轴垂直摆放时，自由落体加速度最大为9.81，当手机沿x、y轴成某个角度摆放时，变量x和y即为该角度的加速度        float percentageX = x / MAX_ACCELEROMETER;//得到当前加速度的比率，如果手机沿x轴垂直摆放，比率为100%，即球在x轴上移动到最大值        float percentageY = y / MAX_ACCELEROMETER;        int pixel_x = (int) (max_x * percentageX);//得到x轴偏移量        int pixel_y = (int) (max_y * percentageY);//得到y轴偏移量        //以球在中心位置的坐标为参考点，加上偏移量，得到球的对应位置，然后移动球到该位置        ball.moveTo(max_x + pixel_x, max_y + pixel_y);    }}

package cn.itcast.accelerometer.view;import android.content.Context;import android.util.AttributeSet;import android.widget.ImageView;public class BallView extends ImageView {public BallView(Context context) {super(context);}    public BallView(Context context, AttributeSet attrs) {        super(context, attrs);    }     public BallView(Context context, AttributeSet attrs, int defStyle) {        super(context, attrs, defStyle);    }     public void moveTo(int x, int y) {        super.setFrame(x, y, x + getWidth(), y + getHeight());//绘制视图，由左上角与右下角确定视图矩形位置    }}

<?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"    >    <TextView        android:layout_width="fill_parent"        android:layout_height="wrap_content"        android:text="Sensor: 0, 0, 0"        android:id="@+android:id/ball_prompt"    />    <FrameLayout        android:layout_width="fill_parent"        android:layout_height="fill_parent"        android:background="@drawable/bg"        android:id="@+android:id/ball_container"    >    <cn.itcast.accelerometer.view.BallView xmlns:android="http://schemas.android.com/apk/res/android"            android:id="@+android:id/ball"            android:src="@drawable/ball"            android:scaleType="center"            android:layout_width="wrap_content"            android:layout_height="wrap_content"        />    </FrameLayout></LinearLayout>

项目源码下载：http://pan.baidu.com/share/link?shareid=275794&uk=1796216265