JAVA GUI ChangeColor.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class ChangeColor extends JPanel implements ActionListener
{
JButton red = new JButton("紅");
JButton orange = new JButton("橙色");
JButton yellow = new JButton("黃");
JButton green = new JButton("變綠色");
JButton blue = new JButton("藍");

public static void main(String[] args)
{
//建立ChangeColor (JPanel 的子類別)物件
ChangeColor p = new ChangeColor();
//將 JPanel 物件加到JFrame("變換視窗背景");
JFrame f = new JFrame("變換視窗背景");
f.getContentPane().add(p);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(360,80);
f.setVisible(true);
}
public ChangeColor()
{
//將五個按鈕元件加到面板中
add(red);
add(orange);
add(yellow);
add(green);
add(blue);
//將五個按鈕的頃聽者都設為此物件
red.addActionListener(this);
orange.addActionListener(this);
yellow.addActionListener(this);
green.addActionListener(this);
blue.addActionListener(this);
}
//五個按鈕的事件處理方法
public void actionPerformed(ActionEvent e)
{
JButton s = (JButton) e.getSource(); //取得產生事件的按鈕
//將面板背景顏色換成按鈕對應的顏色
if(s ==red ) setBackground(Color.red);
else if(s == orange) setBackground (Color.orange);
else if(s == yellow) setBackground (Color.yellow);
else if(s == green) setBackground(Color.green);
else setBackground(Color.blue);
}
}