你的窗口都没有添加WindowListener监听器,你的两个类联系不起来,还有就是根本不关文件名的事,文件名是Login.java就对了,修改过的代码自己看:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
class MyWindowListener implements WindowListener
{
     public void windowClosing(WindowEvent e)
      {
         System.out.println("我退出了！");
         e.getWindow().setVisible(false);
         ((Window)e.getComponent()).dispose();
         System.exit(0);
      }
public void windowActivated(WindowEvent e){}
public void windowClosed(WindowEvent e){}
public void windowDeactivated(WindowEvent e){}
public void windowDeiconified(WindowEvent e){}
public void windowIconified(WindowEvent e){}
public void windowOpened(WindowEvent e){}
}
public class Login
{    public static void main(String arg[])
      {
         Frame f = new Frame("..是你爸爸");
         f.setSize(280,150);
         f.setLayout(null);    
         Button b = new Button("我是你爸爸");
         b.setBounds((f.getWidth()-100)/2,(f.getHeight()-50)/2,100,50);
         f.add(b);
         f.setBackground(Color.lightGray);
         f.setVisible(true);
f.addWindowListener(new MyWindowListener());
      }
}