Question

java applet 绘制五个同心圆 圆与圆之间隔10像素

大家帮帮小弟 刚学谢谢啊

Answer 1

import java.awt.Graphics;

import javax.swing.JFrame;
import javax.swing.JPanel;

/**
*
* 文件名： Draw.java
* 说明：画圆演示
*
*/
public class Draw extends JFrame {

private static final long serialVersionUID = 1L;

//自定义的 panel
MyPanel panel;

Draw() {

MyPanel p = new MyPanel();
this.add(p);
//窗体尺寸
this.setSize(800, 600);
//显示窗体
this.setVisible(true);
//按窗体右上角的关闭按钮结束程序
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

}

class MyPanel extends JPanel {

private static final long serialVersionUID = 1L;
//左上角起点座标，X 和 Y 相同
int x = 100;
//椭圆的宽度和高度相同，就是圆
int r = 200;

/**
* 画图方法
*/
public void paint(Graphics g) {

super.paint(g);
//循环画椭圆
for (int i = 0; i < 5 * 20; i += 20) {
g.drawOval(x + i / 2, x + i / 2, r - i, r - i);
}

}
}
/**
* @param args
*/
public static void main(String[] args) {
new Draw();

}
}

Answer 2

import java.applet.Applet;
import java.awt.Graphics;

public class RoundApplet extends Applet {

int start=50;
int width=100;

public void paint(Graphics g) {
for (int i = 0; i < 5*20; i+=20) {
g.drawOval(start+i/2, start+i/2, width-i, width-i);
}
}

}