容器嵌套的示例

import java.awt.*;public class ExGui3 { private Frame f; private Panel p; private Button bw,bc; private Button bfile,bhelp; public static void main(String args[]) {  ExGui3 gui = new ExGui3();  gui.go(); } public void go() {  f=new Frame("GUI example 3");  bw=new Button("进入Java学习系统");  bc=new Button("编辑工作空间");  f.add(bw,"West");  f.add(bc,"Center");  p=new Panel();  f.add(p,"North");  bfile= new Button("文件");  bhelp=new Button("帮助");  p.add(bfile);  p.add(bhelp);  f.pack();  f.setVisible(true); }}