Java6学习笔记23——使用Swing创建菜单栏

import javax.swing.JFrame;
import javax.swing.JMenuBar;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

public class MenuSimple extends JFrame implements ActionListener {
public static void main(String arg[]) {
MenuSimple ms = new MenuSimple();
}
public MenuSimple() {
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//改变框架关闭时的默认动作为退出
JMenuBar menuBar = buildMenuBar();
setJMenuBar(menuBar);
setSize(300,200);
setLocation(250,150);
setVisible(true);
}
JMenuBar buildMenuBar() {
JMenuBar menuBar = new JMenuBar();

JMenu fileMenu = new JMenu("File");//一级菜单
fileMenu.getPopupMenu().setLightWeightPopupEnabled(false);//当外观显示弹出菜单时，它选择不使用轻量级（纯 Java 的）弹出菜单。
menuBar.add(fileMenu);

JMenuItem openMenuItem = new JMenuItem("Open");//二级菜单
openMenuItem.addActionListener(this);
fileMenu.add(openMenuItem);

JMenuItem saveMenuItem = new JMenuItem("Save");
saveMenuItem.addActionListener(this);
fileMenu.add(saveMenuItem);

JMenuItem exitMenuItem = new JMenuItem("Exit");
exitMenuItem.addActionListener(this);
fileMenu.add(exitMenuItem);

JMenu decideMenu = new JMenu("Decide");//一级菜单
fileMenu.getPopupMenu().setLightWeightPopupEnabled(false);
menuBar.add(decideMenu);

JMenuItem fishMenuItem = new JMenuItem("Fish");
fishMenuItem.addActionListener(this);
decideMenu.add(fishMenuItem);

JMenuItem cutBaitMenuItem = new JMenuItem("Cut Bait");
cutBaitMenuItem.addActionListener(this);
decideMenu.add(cutBaitMenuItem);

return(menuBar);
}
public void actionPerformed(ActionEvent e) {
String selection = e.getActionCommand();
System.out.println(selection);
if(selection.equals("Exit")) {
System.exit(0);
}
}
}