menudemo.java

Java语言

import java.awt.*;
import java.awt.event.*;
public class MenuDemo{
    public static void main(String[] s){
        MenuFrame mf = new MenuFrame("MenuDemo");
        mf.show();  
    }
}
class MenuFrame extends GeneralFrame implements ActionListener{
   MenuItem itemNew, itemOpen;
   MenuItem itemSaveAs, itemSave, itemExit;
   MenuItem itemAbout;
   Menu fMenu, hMenu, vMenu;
   MenuBar menuBar;
   public MenuFrame(String title){
	super(title);
	menuBar = new MenuBar();
	setMenuBar(menuBar);
		
	fMenu = new Menu("File");
	vMenu = new Menu("View");
	hMenu = new Menu("Help");
		
	menuBar.add(fMenu);
	menuBar.add(vMenu);
	menuBar.add(hMenu);
	menuBar.setHelpMenu(hMenu); 
        fMenu.add(itemNew = new MenuItem("New ...",new MenuShortcut(KeyEvent.VK_C)));
        itemNew.addActionListener(this);
        fMenu.add(itemOpen = new MenuItem("Open ...",new MenuShortcut(KeyEvent.VK_O)));
        itemOpen.addActionListener(this);
        fMenu.add(itemSaveAs = new MenuItem("Save As ..."));
        itemSaveAs.addActionListener(this);
        fMenu.add(itemSave = new MenuItem("Save ..."));
        itemSave.addActionListener(this);
        fMenu.addSeparator();
        fMenu.add(itemExit = new MenuItem("Exit"));
        itemExit.addActionListener(this);
		
        hMenu.add(itemAbout = new MenuItem("About …"));
        itemAbout.addActionListener(this);
   }
    public void actionPerformed(ActionEvent e){
	MenuItem item = (MenuItem)e.getSource();
	System.out.println(item.getLabel());
	if(item == itemExit){
		dispose();
		System.exit(0);
	}
   }
}
class GeneralFrame extends Frame {
    GeneralFrame(){
          this("GeneralFrame");
    }
    GeneralFrame(String Title){
          super(Title);
          setSize(getPreferredSize());
	Toolkit tkt = Toolkit.getDefaultToolkit();
	Dimension dim = tkt.getScreenSize();
	int x = dim.width/2 - getSize().width/2;
	int y = dim.height/2 - getSize().height/2;
	setLocation(x, y);	
	addWindowListener(new WindowAdapter(){
		public void  windowClosing (WindowEvent e){
			dispose();
			System.exit(0);
		}
	});
    }	//End of GeneralFrame’Constructor
	
    public Dimension getPreferredSize(){
	return new Dimension(400,300);
    }
}