swing-5-下拉菜单

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

public class test extends JApplet
implements ItemListener{
    JLabel jtf;
    ImageIcon a1, a2, a3;
    public void init(){
        Container contentPane = getContentPane();
        contentPane.setLayout(new FlowLayout());
    
        JComboBox jc = new JComboBox();
        jc.addItem("6");
        jc.addItem("7");
        jc.addItem("8");
        jc.addItemListener(this);
        contentPane.add(jc);
        
        jtf = new JLabel(new ImageIcon("D:/data/Images/6.gif"));
        contentPane.add(jtf);
        
    }
    public void itemStateChanged(ItemEvent ie){
        String s = (String)ie.getItem();
        jtf.setIcon(new ImageIcon("D:/data/Images/"+s+".gif"));
    }

}