java的问题...热心的人来看看

Question

没错呀，这是正确结束程序的方法，使用的是匿名类，也可以这样写
class xxx extends WindowAdapter
{
    public void windowClosing(WindowEvent e)
     { System.exit(0); }
};
然后就可以用下面的代码了：
addWindowlistener(new xxx());
你用的是简洁型的，不过不太容易理解，我以前也没怎么搞懂.

Answer 1

适配器类，没有问题windowClosing事件是指在窗口关闭的时候处理的方法

Answer 2

我把整个代码贴出来吧.....你们帮我看看.....
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class GUIDemo4 extends JPanel
{
     static JFrame frame;
     static String birdString="鸟";
     static String catString="猫";
     static String dogString="狗";
     static String rabbitString="兔";
     JLabel display;
     public GUIDemo4()
     { 
        JRadioButton birdButton=new JRadioButton(birdString);
        birdButton.setMnemonic(KeyEvent.VK_B);
        birdButton.setActionCommand(birdString);
        JRadioButton catButton=new JRadioButton(catString);
        catButton.setMnemonic(KeyEvent.VK_C);
        catButton.setActionCommand(catString);
        JRadioButton dogButton=new JRadioButton(dogString);
        dogButton.setMnemonic(KeyEvent.VK_D);
        dogButton.setActionCommand(dogString);
        JRadioButton rabbitButton=new JRadioButton(rabbitString);
        rabbitButton.setMnemonic(KeyEvent.VK_R);
        rabbitButton.setActionCommand(rabbitString); 
        
        ButtonGroup group=new ButtonGroup();
        group.add(birdButton);
        group.add(catButton);
        group.add(dogButton);
        group.add(rabbitButton);
    
        RadioListener myListener=new RadioListener();
        birdButton.addActionListener(myListener);
        catButton.addActionListener(myListener);
        dogButton.addActionListener(myListener);
        rabbitButton.addActionListener(myListener);   
        
        display=new JLabel("这是RadioButton的一个示例。");
        display.setPreferredSize(new Dimension(180,60));
        
        JPanel radioPanel=new JPanel();
        radioPanel.setLayout(new GridLayout(0,1));
        radioPanel.add(birdButton);
        radioPanel.add(catButton);
        radioPanel.add(dogButton);
        radioPanel.add(rabbitButton);
        
        setLayout(new BorderLayout());
        add(radioPanel,BorderLayout.WEST);
        add(display,BorderLayout.CENTER);
        setBorder(BorderFactory.createEmptyBorder(20,20,20,0));
     }
     
     class RadioListener implements ActionListener
     {
       public void actionPerformed(ActionEvent e)
       {
          display.setText("你选中了"+e.getActionCommand()+"。");
       }
     }
     public static void main(String s[])
     {
       frame=new JFrame("RadioButtonDemo");
       frame.addWindowlistener(new WindowAdapter( )
        {
           public void windowClosing(WindowEvent e){ System.exit(0); }
        });
       frame.getContentPane().add(new GUIDemo4(),BorderLayout.CENTER);
       frame.pack();
       frame.setVisible(true);
     }
} 出错的地方就是
frame.addWindowlistener(new WindowAdapter( )
        {
           public void windowClosing(WindowEvent e){ System.exit(0); }
        });

Answer 3

frame.addWindowlistener(new WindowAdapter( )
是
frame.addWindowListener(new WindowAdapter()
L要大写啦

Answer 4

frame.addWindowlistener(new WindowAdapter( )
        {
           public void windowClosing(WindowEvent e){ System.exit(0); }
        });
中的addWindowlistener中的L应该大写,java 是区分大小写呀。我调试过了，没问题。
结帐，走人了