Question

JAVA新手求教，CardLayout问题

import java.awt.*;
import java.awt.event.*;
class WinCard extends Frame implements ActionListener
{
CardLayout myLay;
Panel pCenter;
Button buttonfirst,buttonlast,buttonnext,buttonexit;
WinCard(String s)
{
setTitle(s);
myLay=new CardLayout();
pCenter=new Panel();
pCenter.setLayout(myLay);
buttonfirst=new Button("第一个");
buttonfirst.addActionListener(this);
buttonlast=new Button("最后一个");
buttonlast.addActionListener(this);
buttonnext=new Button("下一个");
buttonexit=new Button("退出");
buttonexit.addActionListener(this);
for(int i=1;i<=10;i++)
{
pCenter.add("i am"+i,new Button("第"+i+"个"));
}
Panel pSouth=new Panel();
pSouth.add(buttonfirst);
pSouth.add(buttonlast);
pSouth.add(buttonnext);
pSouth.add(buttonexit);
add(pCenter,BorderLayout.CENTER);
add(pSouth,BorderLayout.SOUTH);
setBounds(60,60,300,300);
setVisible(true);
validate();
}
public void actionPerformed(ActionEvent e)
{
if(e.getSource()==buttonfirst)
myLay.first(pCenter);
else if(e.getSource()==buttonlast)
myLay.last(pCenter);
else if(e.getSource()==buttonexit)
System.exit(0);
else if(e.getSource()==buttonnext)
myLay.next(pCenter);
}
}
public class Example7_14
{
public static void main(String args[])
{
WinCard win =new WinCard("窗口");
}
}
点击下一个按钮，不跳转。第一个和最后一个都好用。

Answer 1

马虎的问题
buttonnext没有加监听