1 import java.awt.*;
2 import java.awt.event.ActionEvent;
3 import java.awt.event.ActionListener;
4 import javax.swing.*;
5 public class Main extends JFrame implements ActionListener
6 {
7 private ImagePanel imgPane = null;
8 private JScrollPane scrollPane = null;
9 private JButton zoomin = null ;
10 private JButton zoomout = null;
11 public Main ()
12 {
13 super ("JScrollPane Demo");
14 imgPane = new ImagePanel ("/1.jpg");
15 imgPane.setPreferredSize (new Dimension (600, 400));
16 scrollPane = new JScrollPane (imgPane);
17 scrollPane.setVerticalScrollBarPolicy (JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
18 scrollPane.setHorizontalScrollBarPolicy (JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
19 zoomin = new JButton ("放大");
20 zoomout = new JButton ("缩小");
21 zoomin.setBounds (0,10,60,30);
22 zoomout.setBounds (80,10,60,30);
23 zoomin.addActionListener (this);
24 zoomout.addActionListener (this);
25 imgPane.add (zoomout,JLayeredPane.DRAG_LAYER);
26 imgPane.add (zoomin,JLayeredPane.DRAG_LAYER);
27 this.add (scrollPane);
28 setSize (600, 400);
29 setDefaultCloseOperation (EXIT_ON_CLOSE);
30 setVisible (true);
31 }
32 public static void main ( String[] args )
33 {
34 new Main ();
35 }
36 public void actionPerformed ( ActionEvent e )
37 {
38 if ((JButton) (e.getSource ()) == zoomin)
39 {
40 imgPane.enlarge ();
41 imgPane.setPreferredSize (imgPane.getPreferredSize ());
42 scrollPane.validate ();
43 }
44 else if ((JButton) (e.getSource ()) == zoomout)
45 {
46 imgPane.ensmall ();
47 imgPane.setPreferredSize (imgPane.getPreferredSize ());
48 scrollPane.validate ();
49 }
50 }
51 }
52
53 class ImagePanel extends JLayeredPane
54 {
55 private Dimension theSize = new Dimension (600, 400);
56 private ImageIcon img = null;
57 public ImagePanel (String imgpath )
58 {
59 super ();
60 setLayout (null);
61 this.img = new ImageIcon (getClass ().getResource (imgpath));
62 }
63 public void paintComponent ( Graphics g )
64 {
65 g.clearRect (0, 0, 1024, 768);
66 g.drawImage (img.getImage (), 0, 0, theSize.width, theSize.height,null);
67 }
68 public void enlarge ( )
69 {
70 theSize.width = (theSize.width * 101) / 100;
71 theSize.height = (theSize.height * 101) / 100;
72 setSize (theSize);
73 }
74 public void ensmall ( )
75 {
76 theSize.width = (theSize.width * 100) / 101;
77 theSize.height = (theSize.height * 100) / 101;
78 setSize (theSize);
79 }
80 public Dimension getPreferredSize ( )
81 {
82 return this.theSize;
83 }
84 }
85
posted on 2007-02-13 09:29
-274°C 阅读(1642)
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