example4_8.java

书中的例题

import java.applet.*;
import java.awt.*;
import java.awt.event.*;
class Mycanvas extends Canvas 
{
   int i;
   Mycanvas(int i)
   { 
      setSize(100,160);
	  this.i=i;
   }
   public void paint(Graphics g) 
   { 
     Color c=new Color((30*i)%255,(70*i)%255,(110*i)%255);
     g.setColor(c);
     g.fillOval(80,30,100,100); 
     g.setColor(Color.black);
	 g.drawString("我是第 " + i + " 张卡片",10,150);
   }
} 

public class Example4_8 extends Applet implements ActionListener
 { 
   CardLayout mycard=new CardLayout();
   Button button1=new Button("第一张");
   Button button2=new Button("下一张");
   Button button3=new Button("上一张");
   Button button4=new Button("最后一张");	   
   Mycanvas mycanvas[]=new Mycanvas[11];
   Panel p_card=new Panel();  //定义存放画布Mycanvas的面板 
   
   public void init() 
   { 
      p_card.setLayout(mycard);  //p_card设置为卡片式布局
      p_card.setBackground(Color.cyan);
      for(int i=1;i<=10;i++) 
         { 
		   mycanvas[i]=new Mycanvas(i);
           p_card.add("卡片标号",mycanvas[i]); 
         }
	  button1.addActionListener(this);
      button2.addActionListener(this);
      button3.addActionListener(this);
      button4.addActionListener(this);
      Panel p_button=new Panel();
      p_button.add(button1);
	  p_button.add(button2);
	  p_button.add(button3);
	  p_button.add(button4);
       //设置Applet为边界布局。
	  setLayout(new BorderLayout()); 
	  add(p_card,BorderLayout.CENTER);
	  add(p_button,BorderLayout.SOUTH);
   }

   public void actionPerformed(ActionEvent e)
    {
	  if(e.getSource()==button1)
        {  mycard.first(p_card);
        }
      else if(e.getSource()==button2)
       {  mycard.next(p_card);
       }
      else if(e.getSource()==button3)
       {  mycard.previous(p_card);
       }
      else if(e.getSource()==button4)
       {  mycard.last(p_card);
       }
   }
 }