Java模拟弹球效果(监听键盘)

 1 import java.awt.*;
 2 import java.awt.event.*;
 3 
 4 public class BallGame  extends Frame {
 5     
 6     Image sun = Toolkit.getDefaultToolkit().getImage("sun.jpg");
 7     
 8     double x=200;
 9     double y=200;
10     boolean left,right,up,down;
11     public void paint(Graphics  g){
12         g.drawImage(sun, (int)x, (int)y, null);
13         if(left){
14             x = x-10;
15         }
16         if(right){
17             x = x+10;
18         }
19         if(up){
20             y = y-10;
21         }
22         if(down){
23             y = y+10;
24         }
25         
26     }
27     
28     void launchFrame(){
29         setSize(500,400);
30         setLocation(80, 80);
31         setBackground(Color.black);
32         setTitle("火星十一郎");
33         myEvent();
34         setVisible(true);
35         new PaintThread().start();  
36         addKeyListener(new KeyMonitor());
37     }
38     
39     public static void main(String[] args){  
40         new BallGame().launchFrame();
41     }
42     
43     class PaintThread extends Thread {
44         public void run(){
45             while(true){
46                 repaint();
47                 try {
48                     Thread.sleep(40);
49                 } catch (InterruptedException e) {
50                     e.printStackTrace();
51                 }   //1秒=1000毫秒！
52             }
53         }
54     }
55     
56     class  KeyMonitor extends KeyAdapter {
57         public void keyPressed(KeyEvent e){
58             if(37==e.getKeyCode()){
59                 left=true;
60             }
61             if(39==e.getKeyCode()){
62                 right = true;
63             }
64             if(38==e.getKeyCode()){
65                 up = true;
66             }
67             if(40==e.getKeyCode()){
68                 down = true;
69             }
70         }
71         
72         public void keyReleased(KeyEvent e){
73             if(37==e.getKeyCode()){
74                 left=false;
75             }
76             if(39==e.getKeyCode()){
77                 right = false;
78             }
79             if(38==e.getKeyCode()){
80                 up = false;
81             }
82             if(40==e.getKeyCode()){
83                 down = false;
84             }
85         }
86     }
87     private void myEvent()
88     {
89         this.addWindowListener(new WindowAdapter()//窗口监听
90         {
91             public void windowClosing(WindowEvent e)
92             {
93                 System.exit(0);
94             }
95         });
96     }
97 }