第二篇学习笔记

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

public class checkbox extends JFrame{
 
 private JPanel panel1 = new JPanel();
 private JPanel panel2 = new JPanel();
 private JTextArea jt=new JTextArea(3,10);
 private JCheckBox jc1=new JCheckBox("1");
 private JCheckBox jc2=new JCheckBox("2");
 private JCheckBox jc3=new JCheckBox("3");
 public checkbox(){
  Container c=getContentPane();
  setSize(200,160);
  setVisible(true);
  setTitle("复选框的使用");
  setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
  c.setLayout(new BorderLayout());

  
  c.add(panel1, BorderLayout.NORTH);
  final JScrollPane scrollPane = new JScrollPane(jt);
  panel1.add(scrollPane);


  c.add(panel2, BorderLayout.SOUTH);
  panel2.add(jc1);
  jc1.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent e){
    jt.append("复选框1被选中\n");
   }
  });

  panel2.add(jc2);
  jc2.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent e){
    jt.append("复选框2被选中\n");
   }
  });

  panel2.add(jc3);
  jc3.addActionListener(new ActionListener(){
   public void actionPerformed(ActionEvent e){
    jt.append("复选框3被选中\n");
   }
  });
 }
 
 public static void main(String[] args) {
  new checkbox();

 }

}
程序运行效果图：