CardLayout布局练习（小的图片浏览器）

 1 /*
 2 涉及Panel中的图片的加载，还有Frame的关闭的方法， CardLayout（int hgap, int vgap）就会决定卡片面板的大小
 3 匿名类的使用。。。
 4 */
 5 import java.awt.*;
 6 import java.awt.event.*;
 7 import javax.swing.*;
 8 public class CardLayoutDemo extends Frame{
 9    Panel pCards=new Panel();//卡片面板
10    CardLayout Clayout=new CardLayout(120, 50);//设置卡片和面板边界的垂直和水平距离
11    public CardLayoutDemo(){
12          setLayout(new BorderLayout(100, 20));
13          Panel pBtn = new Panel();//按钮面板
14         
15            pCards.setLayout(Clayout);
16            //pCards.setPreferredSize(new Dimension(30,40));//这句不再起作用了：因为其父类CardLayoutDemo使用的是BorderLayout布局方式，会自动填充
17            pCards.setBackground(Color.red);
18            pBtn.setBackground(Color.yellow);
19        pBtn.setLayout(new FlowLayout(FlowLayout.CENTER, 10, 10));
20            pBtn.setPreferredSize(new Dimension(200, 50));
21 
22           Button tmpB;
23        pBtn.add(tmpB = new Button("第一张"));
24              tmpB.addActionListener(new myActionListener());
25                tmpB.setActionCommand("first");
26        pBtn.add(tmpB = new Button("下一张"));
27              tmpB.addActionListener(new myActionListener());
28                tmpB.setActionCommand("next");
29 
30        pBtn.add(tmpB = new Button("前一张"));
31              tmpB.addActionListener(new myActionListener());
32                tmpB.setActionCommand("previous");
33 
34        pBtn.add(tmpB = new Button("最后一张"));
35              tmpB.addActionListener(new myActionListener());
36                tmpB.setActionCommand("last");
37          
38          
39        for(int i=1; i<=4; ++i){
40               myPanel tmpP;
41             pCards.add(""+i, tmpP=new myPanel(i){
42                   public void paint(Graphics g){
43               g.drawImage(new ImageIcon("zjy"+i+".jpg").getImage(), 20, 0, 300, 400, this);
44              }
45             });
46               tmpP.setBackground(Color.blue);
47               //tmpP.setSize(new Dimension(300, 400));//tmpP接受了匿名类对象，可以通过这种方法更改匿名类的属性
48               //这里不设置的原因是它的大小由CardLayout(int hgap, int vgap)决定了
49          }
50            add(pBtn, "North");
51            add(pCards, "Center");
52    }
53    class myActionListener implements ActionListener{
54     public void actionPerformed(ActionEvent e){
55        String str=e.getActionCommand();
56        if(str.equals("first"))
57            Clayout.first(pCards);
58         else if(str.equals("next"))
59            Clayout.next(pCards);
60         else if(str.equals("previous"))
61            Clayout.previous(pCards);
62         else if(str.equals("last"))
63            Clayout.last(pCards);
64        }
65     } 
66     
67     public static void main(String args[]){
68        CardLayoutDemo myWindow = new CardLayoutDemo();
69        myWindow.setSize(new Dimension(600, 600));
70        myWindow.setResizable(false);
71        myWindow.addWindowListener(new myClosingListener());
72        myWindow.setVisible(true);
73     }
74 }
75 
76 
77 class myClosingListener extends WindowAdapter{
78    public void windowClosing(WindowEvent e){
79       System.exit(0);
80    }
81 }
82 
83 class myPanel extends Panel{
84    int i;
85    public myPanel(int i){
86       this.i=i;
87    }
88 }