Question

在java中如何绘画圆形

Answer 1

/*
* java绘图原理
*/
package Yousphu;
import java.awt.*;
import javax.swing.*;
public class Demo9_1 extends JFrame {
MyPanel mp=null;
public static void main(String[] args) {
// TODO Auto-generated method stub
Demo9_1 demo = new Demo9_1();
}
public Demo9_1()
{
mp=new MyPanel();
this.add(mp);
this.setSize(300, 400);
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setVisible(true);
}
}
//定义一个吗panel、用于绘制和实现图像
class MyPanel extends JPanel
{
//覆盖jpanel的paint方法
//Graphics是汇入的中药类，你可以吧他理解成画笔
public void paint(Graphics g)
{
//调用父类函数进行初始化，绝对不可少
super.paint(g);
//先画一个园
g.drawOval(10, 10, 30, 30);
/*
g.drawRect(30, 30, 40, 40);
g.setColor(Color.blue);
g.drawString("fdsf", 40, 40);*/
//Image im= Toolkit.getDefaultToolkit().getImage(Panel.class.getResource("/aaa.jpg"));
//g.drawImage(im, 20, 20, 200, 200,this);

}
}

Answer 2

Graphics g; //想办法获得图形上下文对象

g.drawOval(x, y, width, height);