jradiobuttondemo.java

Java语言程序设计-源代码（第四部分）和课程相对应的提供了一些用于学习理解的代码设计

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class JRadioButtonDemo extends JFrame{
	JLabel label;
	JRadioButton radioButton1,radioButton2,radioButton3;
	JPanel panel;
	ButtonGroup group;
	public JRadioButtonDemo(){
		super("单选按钮范例");
		Container c=getContentPane();
		//创建标签
		label=new JLabel("请选择：",JLabel.CENTER);
		c.add(label,BorderLayout.CENTER);
		//创建三个单选按钮
		radioButton1=new JRadioButton("China");
		radioButton1.setActionCommand("China");
		radioButton2=new JRadioButton("America");
		radioButton2.setActionCommand("America");
		radioButton3=new JRadioButton("England");
		radioButton3.setActionCommand("England");
		//创建单选按钮组
		group=new ButtonGroup();
		group.add(radioButton1);
		group.add(radioButton2);
		group.add(radioButton3);
		//创建面板
		panel=new JPanel();
		panel.add(radioButton1);
		panel.add(radioButton2);
		panel.add(radioButton3);
		c.add(panel,BorderLayout.SOUTH);		
		//设置监听器
		RadioListener myListener=new RadioListener();
		radioButton1.addActionListener(myListener);
		radioButton2.addActionListener(myListener);
		radioButton3.addActionListener(myListener);
    }
    public static void main(String args[]){
    	JFrame frame=new JRadioButtonDemo();
    	frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    	frame.setSize(250,100);
    	frame.setVisible(true);
    }
    class RadioListener implements ActionListener{
	    public void actionPerformed(ActionEvent e){
		    JRadioButton rb=(JRadioButton)e.getSource();
		    label.setText("您选择的是："+rb.getText());//设置标签上显示的文本
	    }
    }
}