JCheckBoxMenuItem類代表一個複選框，可以包含在一個菜單。選中該複選框菜單更改控製的狀態中，從開到關或從關到開。

類聲明

以下是聲明 javax.swing.JCheckBoxMenuItem類：

public class JCheckBoxMenuItem
   extends JMenuItem
      implements SwingConstants, Accessible

類構造函數

S.N.	構造函數 & 描述
1	JCheckboxMenuItem()  Creates an initially unselected check box menu item with no set text or icon.
2	JCheckboxMenuItem(Action a)  Creates a menu item whose properties are taken from the Action supplied.
3	JCheckboxMenuItem(Icon icon)  Creates an initially unselected check box menu item with an icon.
4	JCheckboxMenuItem(String text)  Creates an initially unselected check box menu item with text.
5	JCheckboxMenuItem(String text, boolean b)  Creates a check box menu item with the specified text and selection state.
6	JCheckboxMenuItem(String text, Icon icon)  Creates an initially unselected check box menu item with the specified text and icon.
7	JCheckboxMenuItem(String text, Icon icon, boolean b)  Creates a check box menu item with the specified text, icon, and selection state.

類方法

S.N.	方法 & 描述
1	AccessibleContext getAccessibleContext()  Gets the AccessibleContext associated with this JCheckBoxMenuItem.
2	Object[] getSelectedObjects() Returns an array (length 1) containing the check box menu item label or null if the check box is not selected.
3	boolean getState()  Returns the selected-state of the item.
4	String getUIClassID()  Returns the name of the L&F class that renders this component.
5	protected String paramString() Returns a string representation of this JCheckBoxMenuItem.
6	void setState(boolean b)  Sets the selected-state of the item.

方法繼承

這個類從以下類繼承的方法：

• javax.swing.JMenuItem

• javax.swing.JAbstractButton

• javax.swing.JComponent

• java.awt.Container

• java.awt.Component

• java.lang.Object

JCheckboxMenuItem 例子

選擇使用任何編輯器創建以下java程序在 D:/ > SWING > com > yiibai > gui >

SwingMenuDemo.java

package com.yiibai.gui;

import java.awt.*;
import java.awt.event.*;

public class SwingMenuDemo {
   private JFrame mainFrame;
   private JLabel headerLabel;
   private JLabel statusLabel;
   private JPanel controlPanel; 

   public SwingMenuDemo(){
      prepareGUI();
   }

   public static void main(String[] args){
      SwingMenuDemo  swingMenuDemo = new SwingMenuDemo();     
      swingMenuDemo.showMenuDemo();
   }
   
   private void prepareGUI(){
      mainFrame = new JFrame("Java SWING Examples");
      mainFrame.setSize(400,400);
      mainFrame.setLayout(new GridLayout(3, 1));

      headerLabel = new JLabel("",JLabel.CENTER );
      statusLabel = new JLabel("",JLabel.CENTER);        

      statusLabel.setSize(350,100);
      mainFrame.addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent windowEvent){
            System.exit(0);
         }        
      });    
      controlPanel = new JPanel();
      controlPanel.setLayout(new FlowLayout());

      mainFrame.add(headerLabel);
      mainFrame.add(controlPanel);
      mainFrame.add(statusLabel);
      mainFrame.setVisible(true);  
   }

   private void showMenuDemo(){
      //create a menu bar
      final JMenuBar menuBar = new JMenuBar();

      //create menus
      JMenu fileMenu = new JMenu("File");
      JMenu editMenu = new JMenu("Edit"); 
      final JMenu aboutMenu = new JMenu("About");
      final JMenu linkMenu = new JMenu("Links");
     
      //create menu items
      JMenuItem newMenuItem = new JMenuItem("New");
      newMenuItem.setMnemonic(KeyEvent.VK_N);
      newMenuItem.setActionCommand("New");

      JMenuItem openMenuItem = new JMenuItem("Open");
      openMenuItem.setActionCommand("Open");

      JMenuItem saveMenuItem = new JMenuItem("Save");
      saveMenuItem.setActionCommand("Save");

      JMenuItem exitMenuItem = new JMenuItem("Exit");
      exitMenuItem.setActionCommand("Exit");

      JMenuItem cutMenuItem = new JMenuItem("Cut");
      cutMenuItem.setActionCommand("Cut");

      JMenuItem copyMenuItem = new JMenuItem("Copy");
      copyMenuItem.setActionCommand("Copy");

      JMenuItem pasteMenuItem = new JMenuItem("Paste");
      pasteMenuItem.setActionCommand("Paste");

      MenuItemListener menuItemListener = new MenuItemListener();

      newMenuItem.addActionListener(menuItemListener);
      openMenuItem.addActionListener(menuItemListener);
      saveMenuItem.addActionListener(menuItemListener);
      exitMenuItem.addActionListener(menuItemListener);
      cutMenuItem.addActionListener(menuItemListener);
      copyMenuItem.addActionListener(menuItemListener);
      pasteMenuItem.addActionListener(menuItemListener);

      final JCheckBoxMenuItem showWindowMenu = 
         new JCheckBoxMenuItem("Show About", true);
      showWindowMenu.addItemListener(new ItemListener() {
         public void itemStateChanged(ItemEvent e) {
            if(showWindowMenu.getState()){
               menuBar.add(aboutMenu);
            }else{
               menuBar.remove(aboutMenu);
            }
         }
      });

      final JRadioButtonMenuItem showLinksMenu = 
         new JRadioButtonMenuItem("Show Links", true);
      showLinksMenu.addItemListener(new ItemListener() {
         public void itemStateChanged(ItemEvent e) {
            if(menuBar.getMenu(3)!= null){
               menuBar.remove(linkMenu);
               mainFrame.repaint();
            }else{                   
               menuBar.add(linkMenu);
               mainFrame.repaint();
            }
         }
      });

      //add menu items to menus
      fileMenu.add(newMenuItem);
      fileMenu.add(openMenuItem);
      fileMenu.add(saveMenuItem);
      fileMenu.addSeparator();
      fileMenu.add(showWindowMenu);
      fileMenu.addSeparator();
      fileMenu.add(showLinksMenu);       
      fileMenu.addSeparator();
      fileMenu.add(exitMenuItem);        
      editMenu.add(cutMenuItem);
      editMenu.add(copyMenuItem);
      editMenu.add(pasteMenuItem);

      //add menu to menubar
      menuBar.add(fileMenu);
      menuBar.add(editMenu);
      menuBar.add(aboutMenu);       
      menuBar.add(linkMenu);

      //add menubar to the frame
      mainFrame.setJMenuBar(menuBar);
      mainFrame.setVisible(true);     
   }

   class MenuItemListener implements ActionListener {
      public void actionPerformed(ActionEvent e) {            
         statusLabel.setText(e.getActionCommand() 
         + " JMenuItem clicked.");
      }    
   }
}

編譯程序，使用命令提示符。到 D:/ > SWING 然後輸出以下命令。

D:SWING>javac comyiibaiguiSwingMenuDemo.java

如果冇有錯誤出現，這意味著編譯成功。使用下麵的命令來運行程序。

D:SWING>java com.yiibai.gui.SwingMenuDemo

驗證下麵的輸出。（點擊文件菜單中取消選取“Show About”菜單項。）