为什么我的“菜单”栏没有显示在我的JFrame“窗口”对象中？

Question

Here I've created the JFrame object, 'window'. And set it to 'true'.

import java.awt.*;

public static void main(String[] args)  {

    JFrame window = new JFrame("GUI Test");

    window.setSize(250, 100);
    window.setLocation(100, 100);

    window.setVisible(true);

Here I've added menu items to the 'menu'. And set visibility as 'true'.

    JMenuItem home = new JMenuItem("Home");
    JMenuItem about = new JMenuItem("About");
    JMenuItem tag = new JMenuItem("Tag");

    JMenu menu = new JMenu("menu");
    menu.add(home);
    menu.add(about);
    menu.add(tag);

    menu.setVisible(true);  


}

I'm not getting any errors. Then what am I missing? Why doesn't my menu display in the 'window' object?

Answer 1

You need to add your JMenu s to a JMenuBar and set to to the JFrame using JFrame#setJMenuBar

See How to use Menus for more details

Answer 2

Frirst creat JMenubar and add the JMenu into that.

 JMenuBar menubar = new JMenuBar();

Add the JMenu into JMenuBar and JMenuar into JFrame to display in the window.

menubar.add(menu);
window.setJMenuBar(menubar);

Answer 3

You need to add JMenuBar with window,

 JMenuBar menuBar= new JMenuBar();

 .....
 menuBar.add(menu);//Add menu with JMenuBar.

 window.setJMenuBar(menuBar);

Answer 4

Add the Jmenu into in you JFrame

window.add(menu);

and also set the layout to JFrame

window.setLayout(new Flawlayout()); // you can try other layout too

And best way is

How to use Menus