ch9_16.java

java图形用户界面设计 包括如何创建窗体 设计界面 管理布局 绘制图形 使用组件 事件编程等

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;
public class ch9_16 extends JFrame implements ItemListener
{
    static JRadioButton jr1;
    static JRadioButton jr2;
    static JRadioButton jr3;
    
    public ch9_16()
    {
        super("测试单选钮");
        setBounds(20,20,600,400);
        getContentPane().setLayout(null);
    }
    public static void main(String [] args)
    {
        ch9_16 f=new ch9_16();
        
        JPanel p=new JPanel();
        p.setBounds(50,50,200,200);       
        p.setBackground(Color.CYAN);
        
        ButtonGroup bg1=new ButtonGroup();
        
        jr1=new JRadioButton("麦当劳");
        jr1.setBounds(20,20,80,50);
        jr1.addItemListener(f);
        jr2=new JRadioButton("肯德基");
        jr2.setBounds(80,20,80,50);
        jr2.addItemListener(f);
        jr3=new JRadioButton("21世界");
        jr3.setBounds(140,20,80,50);
        jr3.addItemListener(f);
        
        bg1.add(jr1);
        bg1.add(jr2);
        bg1.add(jr3);
        
        p.add(jr1);
        p.add(jr2);
        p.add(jr3);
    
        f.getContentPane().add(p);
        f.show();
    }
    public void itemStateChanged(ItemEvent e)
	{
			//判断是否选中
			System.out.println(e.getStateChange());
			//相当于getSource,返回触发事件的组件，用来判断那个组建产生事件
			System.out.println(e.getItemSelectable());
			System.out.println(e.getSource());
			if (e.getSource()== jr1)
			{
				System.out.println("jr1");
			}
			if (e.getSource()== jr2)
			{
				System.out.println("jr2");
			}
			if (e.getSource()== jr3)
			{
				System.out.println("jr3");
			}
			
	}
}