在Java中创建菜单

Question

Is there a way to create a menu in Java GUI? Like for example, I'm using Firefox right now. On the top of the browser, there's a menu with the tabs "File," "Edit," "View," "History," "Bookmarks," "Tools," and "Help." So is there a way to make a similar menu tab in a Java GUI? I'm not quite sure exactly what the component is called, so if someone could point me in the right direction, I'd really appreciate it.

Answer 1

Yes it is possible, with Swing it is called a JMenuBar . And Another link here .

Answer 2

Use JMenuBar, JMenu, and JMenuItem. Here is an example:

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.awt.event.KeyEvent;

import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;

public class SimpleMenu implements ActionListener, ItemListener  {

    public JMenuBar createMenuBar() {
        //create a menubar
        JMenuBar menuBar;
        JMenu filemenu, editmenu;
        JMenu editsubmenu;
        JMenuItem menuItem;

        //Create the menu bar.
        menuBar = new JMenuBar();

        //Build the file menu.
        filemenu = new JMenu("File");
        filemenu.setMnemonic(KeyEvent.VK_F);
        filemenu.getAccessibleContext().setAccessibleDescription("This is the File menu.");
        menuBar.add(filemenu);

        //menu items
        menuItem = new JMenuItem("New",KeyEvent.VK_N);
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        filemenu.add(menuItem);
        menuItem = new JMenuItem("Open File...",KeyEvent.VK_O);
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        filemenu.add(menuItem);
        menuItem = new JMenuItem("Close",KeyEvent.VK_C);
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        filemenu.add(menuItem);     

        //Build the Edit menu.
        editmenu = new JMenu("Edit");
        editmenu.setMnemonic(KeyEvent.VK_E);
        editmenu.getAccessibleContext().setAccessibleDescription("This is the Edit menu.");
        menuBar.add(editmenu);

        //menu items
        menuItem = new JMenuItem("Undo Typing",KeyEvent.VK_U);
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        editmenu.add(menuItem);
        menuItem = new JMenuItem("Redo",KeyEvent.VK_R);
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        editmenu.add(menuItem);
        editsubmenu = new JMenu("Expand Selection To");
        editsubmenu.setMnemonic(KeyEvent.VK_X);
        editsubmenu.addActionListener(this);
        editmenu.add(editsubmenu);

        menuItem = new JMenuItem("Enclosing Element");
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        editsubmenu.add(menuItem);

        menuItem = new JMenuItem("Next Element");
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        editsubmenu.add(menuItem);

        menuItem = new JMenuItem("Previous Element");
        menuItem.getAccessibleContext().setAccessibleDescription("");
        menuItem.addActionListener(this);
        editsubmenu.add(menuItem);

        return menuBar;
    }


    private static void createAndShowGUI() {

        JFrame frame = new JFrame("A Simple Menu");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        SimpleMenu smenu = new SimpleMenu();
        frame.setJMenuBar(smenu.createMenuBar());

        /* show frame */
        frame.pack();
        frame.setSize(400,300);
        frame.setVisible(true);
    }

    public static void main(String[] args) {

        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }

    @Override
    public void itemStateChanged(ItemEvent e) { }

    @Override
    public void actionPerformed(ActionEvent e) {

        JMenuItem jmi = (JMenuItem)e.getSource();
        System.out.println("menu item clicked: " + jmi.getText());
        if (jmi.getText().equalsIgnoreCase("close")) {
            System.exit(0);
        }

    }
}