Java使用GUI繪製線條的範例

package com.yiibai;

import java.awt.*;
import java.awt.event.*;
import java.awt.geom.Line2D;
import javax.swing.JApplet;
import javax.swing.JFrame;

public class DrawAndDisplayLine extends JApplet {
  public void init() {
    setBackground(Color.white);
    setForeground(Color.white);
  }

  public void paint(Graphics g) {
    Graphics2D g2 = (Graphics2D) g;
    g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
    g2.setPaint(Color.gray);
    int x = 8;
    int y = 9;
    g2.draw(new Line2D.Double(x, y, 200, 200));
    g2.drawString("畫一條線的範例", x, 250);
  }

  public static void main(String s[]) {
    JFrame f = new JFrame("畫一條線");
    f.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
    JApplet applet = new DrawAndDisplayLine();
    f.getContentPane().add("Center", applet);
    applet.init();

    f.pack();
    f.setSize(new Dimension(300, 300));
    f.setVisible(true);
  }
}