java程序实现鼠标绘图

 1 import java.awt.*;
 2 
 3 import javax.swing.*;
 4 class Gstudy extends JFrame{
 5     
 6     private int x1,y1,x2,y2;
 7     private newPanel panel=new newPanel();
 8     private JButton btn=new JButton("清除");
 9     public Gstudy()
10     {
11         setTitle("交互式绘图");
12         setBounds(10,10,750,700);
13         btn.addActionListener(new ClearList());
14         panel.add(btn,BorderLayout.SOUTH);
15         add(panel);
16     }
17     public static void main(String[] args)
18     {
19         Gstudy frm=new Gstudy();
20         frm.setVisible(true);
21         frm.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
22     }
23     private class ClearList  implements ActionListener
24     {
25         @Override
26         public void actionPerformed(ActionEvent e) {
27             
28             panel.paintComponent(panel.getGraphics());
29         }
30     }
31     private class MyMouseList extends MouseAdapter
32     {
33         public void mousePressed(MouseEvent e)
34         {
35             x1=e.getX();
36             y1=e.getY();
37         }
38     }
39     private class MyMouseMotionList extends MouseMotionAdapter
40     {
41         public void mouseDragged(MouseEvent e)
42         {
43             x2=e.getX();
44             y2=e.getY();
45             Graphics g=panel.getGraphics();
46             g.drawLine(x1, y1, x2, y2);
47             x1=x2;
48             y1=y2;
49         }
50     }
51     private class newPanel extends JPanel
52     {
53         
54         public newPanel()
55         {
56             this.addMouseMotionListener(new MyMouseMotionList());
57             this.addMouseListener(new MyMouseList());
58         }
59         @Override
60         protected void paintComponent(Graphics g) {
61             // TODO Auto-generated method stub
62             super.paintComponent(g);
63         }
64         
65     }