MenuItem的作用

Question

我想要创建一个程序，它包含有三个选项的菜单：

• 联系人
• 日期
• 帮助

哪一个选项有子选项。

因此，当我从第一个子选项的第一个选项中选择"New"时，我想添加我的客户信息。

我用item menu来做这个。这就是我下面的代码，正如您所看到的:我必须使用什么方法来完成这个操作，以及之后的其他操作呢？

   class angenda{
    private String name;
    private String surname;
    private int telephone;

    public angenda(){
        name="";
        surname="";
        telephone=0;        
    }

    public void setName(String n) {
        n=name;
    }
    public String getName() {
        return name;
    }
    public void setSurname(String s) {
        s=surname;
    }
    public String getSurname() {
        return surname;
    }
    public void setTelephone(int t) {
        t=telephone;
    }
    public int getTelephone() {
        return telephone;
    }
}
public class Main extends Frame {

     MenuBar bar;
     Menu Contacts,Dates,Help;
     MenuItem itemContacts[],itemDates[],itemHelp[];     
     TextField name;
     TextField surname;
     TextField telephone;
    public static void main(String[] args) {
        Main m=new Main();
        m.show();
        m.setTitle("e-agenda");
        m.setSize(500, 500);
        //an to sintajo etsi:
        //JFrame f = new JFrame()


    }
    Main() {        
        setLayout(new FlowLayout());
        itemContacts=new MenuItem[6];   
        itemDates=new MenuItem[4];
        itemHelp=new MenuItem[4];
        itemContacts[0]=new MenuItem("New");
        itemContacts[1]=new MenuItem("Load");
        itemContacts[2]=new MenuItem("Save");
        itemContacts[3]=new MenuItem("Delete");
        itemContacts[4]=new MenuItem("Update");
        itemContacts[5]=new MenuItem("Exit");

        itemDates[0]=new MenuItem("New");
        itemDates[1]=new MenuItem("Load");
        itemDates[2]=new MenuItem("Save");
        itemDates[3]=new MenuItem("Cancel");
        itemHelp[0]=new MenuItem("sss");
        itemHelp[1]=new MenuItem("Info");

        Contacts=new Menu("CONTACTS");
        Dates=new Menu("DATES");
        Help=new Menu("HELP");
        for(int i=0; i<6; i++) {            
            Contacts.add(itemContacts[i]);          
        }
        for (int i=0; i<4; i++)     {
            Dates.add(itemDates[i]);            
        }
        for (int i=0; i<2; i++)     {
            Help.add(itemHelp[i]);
        }
        bar=new MenuBar();
        bar.add(Contacts);
        bar.add(Dates);
        bar.add(Help);
        setMenuBar(bar);            


    }   

    public boolean action(Event event, Object arg) {
        if(event.target instanceof MenuItem)
        {
            String text=(String)arg;            
            if (text.equals("New")) {
                name.getText();
            }
            if(text.equals("Exit")) {
                System.exit(0);
            }

        }
        else
            super.action(event, arg);
        return true;    


    }

}

谢谢。

Answer 1

public class MenuDemo extends JFrame implements ActionListener {

    public static void main(String... args) {
        SwingUtilities.invokeLater(() -> new MenuDemo().setVisible(true));
    }

    public MenuDemo() {
        init();
    }

    private void init() {
        setLayout(new BorderLayout(5, 5));
        add(new JScrollPane(createMainPanel()), BorderLayout.CENTER);
        setJMenuBar(createMenuBar());
        setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        setTitle("e-agenda");
        setSize(500, 500);
        centerToScreen();
    }

    public void centerToScreen() {
        Dimension size = getToolkit().getScreenSize();
        setLocation(size.width / 2 - getWidth() / 2, size.height / 2 - getHeight() / 2);
    }

    private JPanel createMainPanel() {
        JPanel panel = new JPanel();
        panel.setBackground(Color.gray);
        return panel;
    }

    private JMenuBar createMenuBar() {
        JMenuBar menuBar = new JMenuBar();
        menuBar.add(createContactsMenu());
        menuBar.add(createDatesMenu());
        menuBar.add(createHelpMenu());
        return menuBar;
    }

    private static final String MENU_CONTACTS_NEW = "contacts.new";
    private static final String MENU_CONTACTS_LOAD = "contacts.load";
    private static final String MENU_CONTACTS_SAVE = "contacts.save";
    private static final String MENU_CONTACTS_DELETE = "contacts.delete";
    private static final String MENU_CONTACTS_UPDATE = "contacts.update";
    private static final String MENU_CONTACTS_EXIT = "contacts.exit";

    private JMenu createContactsMenu() {
        JMenu menu = new JMenu("Contacts");
        menu.add(createMenuItem("New", MENU_CONTACTS_NEW));
        menu.add(createMenuItem("Load", MENU_CONTACTS_LOAD));
        menu.add(createMenuItem("Save", MENU_CONTACTS_SAVE));
        menu.add(createMenuItem("Delete", MENU_CONTACTS_DELETE));
        menu.add(createMenuItem("Update", MENU_CONTACTS_UPDATE));
        menu.add(createMenuItem("Exit", MENU_CONTACTS_EXIT));
        return menu;
    }

    private static final String MENU_DATES_NEW = "dates.new";
    private static final String MENU_DATES_LOAD = "dates.load";
    private static final String MENU_DATES_SAVE = "dates.save";
    private static final String MENU_DATES_CANCEL = "dates.cancel";

    private JMenu createDatesMenu() {
        JMenu menu = new JMenu("Dates");
        menu.add(createMenuItem("New", MENU_DATES_NEW));
        menu.add(createMenuItem("Load", MENU_DATES_LOAD));
        menu.add(createMenuItem("Save", MENU_DATES_SAVE));
        menu.add(createMenuItem("Cancel", MENU_DATES_CANCEL));
        return menu;
    }

    private static final String MENU_HELP_INFO = "help.info";

    private JMenu createHelpMenu() {
        JMenu menu = new JMenu("Help");
        menu.add(createMenuItem("Info", MENU_HELP_INFO));
        return menu;
    }

    private JMenuItem createMenuItem(String text, String actionCommand) {
        JMenuItem item = new JMenuItem(text);
        item.setActionCommand(actionCommand);
        item.addActionListener(this);
        return item;
    }

    @Override
    public void actionPerformed(ActionEvent event) {
        String command = event.getActionCommand();
        System.out.println(command);

        if (MENU_CONTACTS_EXIT.equals(command))
            onCommandsExit();
    }

    private void onCommandsExit() {
        dispose();
    }
}