1 import java.awt.Frame.*;
2 import java.awt.event.*;
3 import java.awt.*;
4
5 public class Test extends Frame {
6
7 boolean mouseClicked = false;
8
9 public void launchFrame() {
10 this.setLocation(100,100);
11 this.setBackground(Color.GRAY);
12 this.setSize(500, 300);
13 this.addMouseListener(new mouseMonitor());
14 this.setVisible(true);
15 }
16
17 public void paint(Graphics g) {
18 Color c = g.getColor();
19 if(mouseClicked == false) {
20 g.setColor(Color.WHITE);
21 g.drawLine(100, 100, 400, 100);
22 g.drawLine(100, 100, 100, 200);
23 g.setColor(Color.BLACK);
24 g.drawLine(100, 200, 400, 200);
25 g.drawLine(400, 100, 400, 200);
26 }
27 else if(mouseClicked == true) {
28 g.setColor(Color.BLACK);
29 g.drawLine(100, 100, 400, 100);
30 g.drawLine(100, 100, 100, 200);
31 g.setColor(Color.WHITE);
32 g.drawLine(100, 200, 400, 200);
33 g.drawLine(400, 100, 400, 200);
34 }
35 g.setColor(c);
36 }
37
38 public class mouseMonitor extends MouseAdapter {
39 public void mousePressed(MouseEvent e) {
40 if(e.getX()<400 && e.getX()>100 && e.getY()<200 && e.getY()>100) { //getX()和getY()是MouseEvent的方法
41 mouseClicked = true;
42 repaint(); // 这里一定记得repaint()
43 }
44 }
45 public void mouseReleased(MouseEvent e) {
46 mouseClicked = false;
47 repaint();
48 }
49
50 }
51
52 public static void main(String[] args) {
53 Test t = new Test();
54 t.launchFrame();
55 }
56 }
