guliusuo
发贴: 28
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于 2006-09-21 16:48
import java.awt.*; import java.awt.event.*; public class W2 extends Frame{ W2(){ super("管理系统"); setSize(750,550); setVisible(true); addWindowListener(new Win()); } class Win extends WindowAdapter{ public void windowClosing(WindowEvent e){ System.exit(0); } } public static void main(String args[]){ new W2(); } } 疑问: WindowAdapter的定义: public abstract class WindowAdapter extends Object implements WindowListener{ public WindowAdapter(); public void windowOpened(WindowEvent e); public void windowClosing(WindowEvent e); public void windowClosed(WindowEvent e); public void windowIconified(WindowEvent e); public void windowDeiconified(WindowEvent e); public void windowActivated(WindowEvent e); public void windowDeactivated(WindowEvent e); } WindowAdapter是个抽象类,程序中的子类Win只覆盖了父类(也就是这里的抽象类)中的一个方法 public void windowClosing(WindowEvent e),这样的Win类按道理应该还是抽象类,但是在这个程序里却可以将其实例化。而且很奇怪,它具然可以通过编译,并运行! 有哪位高手知道这是怎么回事!!! 请求帮助!
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