package com.bjsxt;//scr中新建的包package
import java.awt.*;
import javax.swing.*;

public class BallGame extends JFrame {
        Image ball=Toolkit.getDefaultToolkit().getImage("images/ball.png");
        Image desk=Toolkit.getDefaultToolkit().getImage("images/desk.png");
        double x=200;
        double y=200;
        double degree=3.14/3;
        //绘制窗口
    public void paint(Graphics g){
        System.out.println("窗口被绘制了一次。");
        g.drawImage(desk,0,0,null);
        g.drawImage(ball,(int)x,(int)y,null);
        x=x+10*Math.cos(degree);
        y=y+10*Math.sin(degree);
        //碰到上下边界
        if(y>501-40-30||y<0+40+30){
            degree=-degree;
        }
        //碰到左右边界
        if(x>856-40-30||x<0+40+30) {
            degree = 3.14 - degree;
        }
    }
        //创建窗口
        void launchFrame(){
            setSize(856,501);
            setLocation(100,100);
            setVisible(true);
            //实现动画，每秒绘制窗口25次
            while(true){
                repaint();
                try {
                    Thread.sleep(40);//1s=1000ms,大约1s绘制25次
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
        public static void main(String[] args){
            System.out.println("我的小游戏开始了！");
            BallGame game=new BallGame();
            game.launchFrame();
        }

}