add two at the beginning, set the second to be invisible.
when you detect the value change event,
comb2.clearAll();
comb2.add(whatever);
comb2.setvisible(true);
when you detect the value change event,
comb2.clearAll();
comb2.add(whatever);
comb2.setvisible(true);
import javax.swing.*;
import javax.swing.event.*;
import java.awt.*;
/*
<applet code=test.class codebase=F:/j/ width=200 height=300 >
</applet>
*/
public class test extends JApplet implements ListSelectionListener
{
JList lt;
JList lt2;
Container conPane;
JScrollPane jsp2;
public void init()
{
conPane=getContentPane();
String[] items=new String[12];
for(int i=0; i<11; i++)
items[i]="ii";
lt=new JList(items);
lt2=new JList(items);
JScrollPane jsp=new JScrollPane(lt);
lt.setVisibleRowCount(5);
lt.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
lt.addListSelectionListener(this);
jsp2=new JScrollPane(lt2);
lt2.setVisibleRowCount(5);
lt2.setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
lt2.addListSelectionListener(this);
conPane.setLayout(new FlowLayout());
conPane.add(jsp);
conPane.add(jsp2);
jsp2.setVisible(false);
}
public void valueChanged(ListSelectionEvent e)
{
int[] index=lt.getSelectedIndices();
String[] items=new String[12];
jsp2.setVisible(true);
repaint();
}
}