教大家使用 Java 画圆

import java.awt.*; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; /** * @author erniu.wzh */ public class AWTGraphicsDemo extends Frame { public AWTGraphicsDemo() { super("Circle"); prepareGUI(); } public static void main(String[] args) { AWTGraphicsDemo awtGraphicsDemo = new AWTGraphicsDemo(); awtGraphicsDemo.setVisible(true); } private void prepareGUI() { setSize(1000, 1000); addWindowListener(new WindowAdapter() { @Override public void windowClosing(WindowEvent windowEvent) { System.exit(0); } }); } @Override public void paint(Graphics g) { draw(g, 500, 900, 0); } private void draw(Graphics g, double x, double y, double s) { if (s > 3.14 * 2) { return; } point(g, x, y); s += 0.314 / 180; draw(g, x + Math.cos(s) * 400 * 0.314 / 180, y - Math.sin(s) * 400 * 0.314 / 180, s); } private void point(Graphics g, double x, double y) { g.drawLine((int) x, (int) y, (int) x, (int) y); } }