check.java.txt

所上载的是一个可以实现单选框功能的小程序.

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

/*
 * 这是一个现实单选框的小程序
 */

public class Check extends JApplet
{
  JRadioButton rb1=new JRadioButton("rb1");
  JRadioButton rb2=new JRadioButton("rb2");
  JRadioButton rb3=new JRadioButton("rb3");
  JTextArea txt=new JTextArea("t1",10,10);
  JScrollPane txtsrl=new JScrollPane(txt,JScrollPane.VERTICAL_SCROLLBAR_NEVER,
                                    JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
 ButtonGroup bg=new ButtonGroup();
  ActionListener rbln=new ActionListener()
  {
    public void actionPerformed(ActionEvent e)
    {
      JRadioButton nowrb=(JRadioButton)e.getSource();
      if (nowrb.isSelected())
      {
        txt.append(nowrb.getText()+"is selected\n");
      }

    }
  };

    public void init()
    {
      rb1.addActionListener(rbln);
      rb2.addActionListener(rbln);
      rb3.addActionListener(rbln);
      bg.add(rb1);
      bg.add(rb2);
      bg.add(rb3);



      Container cp=getContentPane();
      cp.setLayout(new FlowLayout());
      cp.add(rb1);
      cp.add(rb2);
      cp.add(rb3);
      cp.add(txt);
      cp.add(txtsrl);

    }
    




}