example12_4.java.bak

不错的教程 适合中高级人员的使用

import java.applet.*;import java.awt.*;import java.awt.event.*;
class Mycanvas extends Canvas 
{  int x,y;
   Mycanvas(int a,int b)
   {  x=a;y=b;
      setSize(100,160);
   }
   public void paint(Graphics g) 
   {  g.setColor(Color.red);
      g.fillOval(50,50,4*x,4*y);//画实心椭圆
      g.drawString("我是第 "+x,10,150);
   }
} 
public class Example12_3 extends Applet implements ActionListener
{  CardLayout mycard;
   Button button1,button2,button3;
   Mycanvas mycanvas[];
   Panel p; 
   public void init() 
   {  setLayout(new BorderLayout()); //小容器的布局是边界布局。
      mycard=new CardLayout();
      p=new Panel();
      p.setLayout(mycard);          //p的布局设置为mycard（卡片式布局）
      button1=new Button("first");
      button2=new Button("next");
      button3=new Button("last one"); 
      mycanvas=new Mycanvas[21]; 
      for(int i=1;i<=20;i++) 
         { mycanvas[i]=new Mycanvas(i,i);
           p.add("i am"+i,mycanvas[i]); 
         }
      button1.addActionListener(this);
      button2.addActionListener(this);
      button3.addActionListener(this);
      Panel p2=new Panel();
      p2.add(button1);p2.add(button2);p2.add(button3);
      add(p,BorderLayout.CENTER);add(p2,BorderLayout.SOUTH);
   }
   public void actionPerformed(ActionEvent e)
   {  if(e.getSource()==button1)
        {  mycard.first(p);
        }
      else if(e.getSource()==button2)
       {  mycard.next(p);
       }
      else if(e.getSource()==button3)
       {  mycard.last(p);
       }
   }
}