为什么我的菜单下拉列表名称不显示Java

Question

I'm doing a program where I'm working with getting the menu's to appear, but for some reason I can't seem to get the names for my menu drop downs to appear.I would greartly appreciante some help with this matter.

public class Application extends JPanel implements  ActionListener{

JPanel p;
JFrame f;
JMenu m;
JMenu m2;
JMenuBar menu;
JMenuItem item;
JMenuItem item2;

Application()
{
    super();
    //creating panel
    f=new JFrame("CMPSC 221 Exam 2 ");
    f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    f.setSize(200,200);
    f.setContentPane(new JDesktopPane());


    m2 =  new JMenu();

    menu = new JMenuBar();
    m = new JMenu();
    //adding the the drop down menu
    m.setName("File");
    m.add("New");
    m.addSeparator();
    m.add("Open");
    menu.add(m);
    m2.setName("Edit");
    m2.add("Copy");
    m2.addSeparator();
    m2.add("Paste");
    menu.add(m2);


    menu.setVisible(true);
    f.setJMenuBar(menu);





    f.setVisible(true);


}

Answer 1

不要使用m.setName将名称传递给JMenu()构造函数