以上是我寫的一段簡單的代碼 其中監聽器的作用 是讓下拉菜單中顯示 數組love中的元素 數組只能在初始化時操package lucky.first.lianxi;import java.awt.*;import java.awt.event.*;import java.util.*;import javax.swing.*;public class lianxi132 extends JFrame{private JPanel panel1=new JPanel();private JPanel panel2=new JPanel();static String love[];public static void shuzu(){lianxi132 l=new lianxi132();l.love={"身份證號","軍人證號","護照號"};}public lianxi132(){setTitle("監聽");setSize(200,150);setVisible(true);Container cp=getContentPane();JComboBox jc=new JComboBox(new MycomboBox());JButton jb=new JButton("顯示吧 MY主！");jb.setPreferredSize(new Dimension(150,20));jb.addActionListener(new jbAction());setLayout(new BorderLayout());panel1.add(jc);panel2.add(jb);cp.add(BorderLayout.NORTH,panel1);cp.add(BorderLayout.CENTER,panel2); }class jbAction implements ActionListener{public void actionPerformed(ActionEvent arg0){lianxi132 b=new lianxi132();b.shuzu();}}class MycomboBox extends AbstractListModel implements ComboBoxModel{String selecteditem=null;public Object getElementAt(int i){return love[i];}public int getSize(){return love.length;}public void setSelectedItem(Object item){selecteditem=(String)item;}public Object getSelectedItem(){return selecteditem;}}public static void main(String[] args){new lianxi132();}}