jcombobox4.java

《精通Java Swing程序设计S》这本书所附带的JAVA程序写得很漂亮,都是SWING的实例子,很适合初学者。

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class JComboBox4
{
    String[] s = {"西瓜","苹果","草莓","香蕉","葡萄"};
    
    public JComboBox4()
    {
        JFrame f = new JFrame("JComboBox");
        Container contentPane = f.getContentPane();
        
        JComboBox combo = new JComboBox(s);
        combo.setBorder(BorderFactory.createTitledBorder("您喜欢吃哪些水果？"));
        combo.setRenderer(new ACellRenderer());
        combo.setMaximumRowCount(3);
        
        contentPane.add(combo);
        f.pack();
        f.show();
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                    System.exit(0);
            }
        });
    }
    
    public static void main(String args[])
    {
        new JComboBox4();
    }
    
}

class ACellRenderer extends JLabel implements ListCellRenderer
{
    ACellRenderer()
    {
        setOpaque(true);
    }
    
    public Component getListCellRendererComponent(JList list,
                                                  Object value,
                                                  int index,
                                                  boolean isSelected,
                                                  boolean cellHasFocus)
    {
        if (value != null)
        {
            setText(value.toString());
            setIcon(new ImageIcon(".\\icons\\fruit"+(index+1)+".jpg"));
        }
        if (isSelected) {
            setBackground(list.getSelectionBackground());
            setForeground(list.getSelectionForeground());
        }
        else {
            setBackground(list.getBackground());
            setForeground(list.getForeground());
        }

        return this;
    }    
}