JAVA 里的Canvas类

来源：互联网发布：数据库几种冗余编辑：程序博客网时间：2024/05/18 03:08

package cn.canvas;

import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Panel;
import java.awt.event.*;
import java.awt.Canvas;
import java.io.Closeable;
public class canvas
{
   Frame f1=new Frame("简单绘图");
   Panel p1=new Panel();
   Button bt1=new Button("绘制矩形");
   Button bt2=new Button("绘制圆形");
   Button bt3=new Button("清空");
   Mycanvas drawArea1=new Mycanvas();
   Mycanvas drawArea2=new Mycanvas();
   public void set()
   {
       p1.add(bt1);
       p1.add(bt2);
       p1.add(bt3);
       bt3.addActionListener(new ActionListener()
       {
           public void actionPerformed(ActionEvent e)
           {
               drawArea1.repaint();
               System.out.println("我靠！");
               System.exit(0);
           //   drawArea1.update(g);
           }
       });
       f1.add(p1,BorderLayout.SOUTH);
       drawArea1.setPreferredSize(new Dimension(250,180));
       drawArea2.setPreferredSize(new Dimension(300,180));
       f1.add(drawArea1,BorderLayout.EAST);
       f1.add(drawArea2,BorderLayout.WEST);
       f1.pack();
       f1.setVisible(true);
   }
   public static void main(String args[])
   {
       new canvas().set();
   }
   class Mycanvas extends Canvas
   {
       public void paint(Graphics g)
       {
           g.drawRect(80,60,150,10);
           g.drawOval(100,70,100,100);
       }
       public void update(Graphics g)
       {

       }
   }
}