buttonclick2.java

《JAVA程序设计教程》源代码

//ButtonClick2.java

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

public class ButtonClick2
{
	public static void main(String[] args)
	{  
		ButtonFrame frame = new ButtonFrame();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.show();
	}
}

class ButtonFrame extends JFrame
{
	public ButtonFrame()
	{
		setTitle("ButtonClick2");
		setSize(WIDTH, HEIGHT);
		
		// 将panel加入到frame
		ButtonPanel panel = new ButtonPanel();
		Container contentPane = getContentPane();
		contentPane.add(panel);
	}
	
	public static final int WIDTH = 300;
	public static final int HEIGHT = 200;  	
}

class ButtonPanel extends JPanel
	implements ActionListener
{  
	public ButtonPanel()
	{  
		//创建按钮
		Button1 = new JButton("按钮一");
		Button2 = new JButton("按钮二");
		
		//将按钮加入panel
		add(Button1);
		add(Button2);
		
		//注册监听器
		Button1.addActionListener(this);
		Button2.addActionListener(this);
	}
	
	public void paintComponent(Graphics g)
	{  
		super.paintComponent(g);

		//显示用户的点击操作
		g.drawString("您点击的是：" + ButtonText, 90, 120);
	}
	
	public void actionPerformed(ActionEvent event)
	{  
		Object source = event.getSource();
		if (source == Button1) ButtonText = "按钮一";
		else if (source == Button2) ButtonText = "按钮二";
		repaint();
	}

	private JButton Button1;
	private JButton Button2;
	public String ButtonText = "";
}