JcomboBox下拉框事件监听怎么写？麻烦举个简单例子说明？

Question

JcomboBox下拉框事件监听怎么写？麻烦举个简单例子说明？

Answer 1

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;public class JComboBoxFrame extends JFrame
{
private JComboBox cb = new JComboBox();

public JComboBoxFrame()
{
cb.addItem("1");
cb.addItem("2");
cb.addItem("3");

cb.addItemListener(new ItemListener()
{
public void itemStateChanged(ItemEvent event)
{
switch (event.getStateChange())
{
case ItemEvent.SELECTED: 
System.out.println("选中" + event.getItem());
break;
case ItemEvent.DESELECTED:
System.out.println("取消选中" + event.getItem());
break;
}
}
});

add(cb);
}

public static void main(String[] args)
{
JFrame frame = new JComboBoxFrame();
frame.pack();
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
}