testjcombobox.java

一个GUI编程的例子 一个GUI编程的例子

import java.awt.*; 
 import java.awt.event.*; 
 import javax.swing.*; 
 public class TestJComboBox { 
     public TestJComboBox() {     
     }  
      public static void main(String []args) 
      { 
       MyFrame f=new MyFrame(); 
       f.setVisible(true); 
      }   
 } 
 class MyFrame extends JFrame implements ActionListener{ 
  JComboBox jc1; 
  public MyFrame(){ 
   this.setBounds(80,60,600,300); 
   this.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); 
   this.setLayout(new FlowLayout()); 
   //因为你要放置控件到窗体上,首先要得到控件的容器 
   Container c=this.getContentPane(); 
   //建立下拉列表框的对象 
   JComboBox jc=new JComboBox(); 
   //在下拉列表框中加入内容 
   jc.addItem("A"); 
   jc.addItem("B"); 
   jc.addItem("C"); 
     
   //利用数组建立下拉列表 
   //形成数组 
   String [] fruit={"apple","banana","lemon"}; 
   jc1=new JComboBox(fruit); 
   jc1.addActionListener(this); 
   JButton jb=new JButton("确定"); 
   jb.addActionListener(this); 
   //放置到容器 
   c.add(jc); 
   c.add(jc1); 
   c.add(jb); 
   
  } 
  
  public void actionPerformed(ActionEvent e) { 
   
   JOptionPane.showMessageDialog(this,jc1.getSelectedIndex() ,"提示",JOptionPane.OK_OPTION); 
   JOptionPane.showMessageDialog(this,jc1.getSelectedItem().toString() ,"提示",JOptionPane.OK_OPTION); 
   
  } 
 }