JAVA GUI ColorShape.java

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

public class ColorShape extends JPanel
{
public void paintComponent(Graphics g)
{
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
//根據 MyPanel 的寬與高調整圖案大小
float Width = getSize().width - 10;
float Height = getSize().height/3 - 10;
// 畫兩條紅色線
g2.setPaint(Color.red);
g2.draw(new Line2D.Float(5,5,5+Width,5+Height));
g2.draw(new Line2D.Float(5,5+Height,5+Width,5));
//畫自訂顏色的的舉形
g2.setPaint(new Color(192,128,64));
g2.fill(new Rectangle2D.Float(5,10+Height,Width,Height));
//畫建層橢圓
g2.setPaint(new GradientPaint(5,5,Color.blue,5+Width,5,Color.yellow));
g2.fill(new Ellipse2D.Float(5,20+2*Height,Width,Height));

}
public static void main(String[] args)
{
JFrame f = new JFrame("色彩應用");
ColorShape p = new ColorShape();
p.setBackground(Color.white); //將背景設為白色
f.getContentPane().add(p);
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
f.setSize(640,480);
f.setVisible(true);
}
}