在Java的GUI编程中，如何使用GUI绘制多边形？
以下示例演示如何通过创建Polygon()对象来绘制多边形。addPoint()和drawPolygon()方法用于绘制多边形。
package com.yiibai;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class DisplayPolygon extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
Polygon p = new Polygon();
for (int i = 0; i < 5; i++)
p.addPoint((int) (100 + 50 * Math.cos(i * 2 * Math.PI / 5)),
(int) (100 + 50 * Math.sin(i * 2 * Math.PI / 5)));
g.drawPolygon(p);
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.setTitle("Polygon");
frame.setSize(350, 250);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = frame.getContentPane();
contentPane.add(new DisplayPolygon());
frame.setVisible(true);
}
}
上述代码示例将产生以下结果。
示例-2
以下是使用GUI绘制多边形的另一个示例。
package com.yiibai;
import java.awt.Color;
import java.awt.Container;
import java.awt.Graphics;
import java.awt.Polygon;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import javax.swing.JFrame;
import javax.swing.JPanel;
public class DisplayPolygon2 extends JPanel {
public void paintComponent(Graphics g) {
super.paintComponent(g);
Polygon p = new Polygon();
for (int i = 0; i < 5; i++)
p.addPoint((int) (100 + 50 * Math.cos(i * 2 * Math.PI / 5)),
(int) (100 + 50 * Math.sin(i * 2 * Math.PI / 5)));
g.drawPolygon(p);
}
public static void main(String[] args) {
JFrame frame = new JFrame();
frame.getContentPane().setBackground(Color.YELLOW);
frame.setTitle("使用GUI绘制多边形");
frame.setSize(350, 250);
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
Container contentPane = frame.getContentPane();
contentPane.add(new DisplayPolygon2());
frame.show();
}
}
上述代码示例将产生以下结果。
