java - 设置菜单对象的布局

Question

我无法设置新的窗口布局。我有一个菜单和子菜单。我的子菜单上有一个 Action 监听器，它引导我进入新窗口。问题是我无法将其设置为给定的布局。这是我的代码:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Converter extends JFrame
{
    private static final long serialVersionUID = 1L;
    private MoneyDetails convertMe = new MoneyDetails();
    private JLabel tlLabel = new JLabel("     Amount of TL");
    private JLabel dollarsLabel = new JLabel("Amount of Dollars");
    private JTextField tlField = new JTextField("0.0");
    private JTextField dollarsField = new JTextField("0.0");
    private JButton tlButton = new JButton("Convert to $");
    private JButton dollarsButton = new JButton("<<< Convert to TL");
    private JButton setRates = new JButton("Set Rates");

    private JMenuBar menuBar = new JMenuBar(); // Window menu bar
    public Converter(String title) {
        setTitle(title);
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setJMenuBar(menuBar); // Add the menu bar to the window
        JMenu fileMenu = new JMenu("File"); // Create File menu
        JMenu elementMenu = new JMenu("Elements"); // Create Elements menu
        JMenuItem subTest = new JMenuItem("Test");

        // Here is the problem
        subTest.addActionListener(new ActionListener(){     
            public void actionPerformed(ActionEvent actionEvent){
                Converter convert = new Converter();

                GridLayout expLay = new GridLayout(2,2,12,6);
                convert.setLayout(expLay);
                convert.getLayout();
                convert.doLayout();
                convert.setVisible(true);
            }
        });

        menuBar.add(fileMenu); // Add the file menu
        menuBar.add(elementMenu); // Add the element menu
        fileMenu.add(subTest);
    }

    public Converter()
    {
        JPanel dataPanel = new JPanel(new GridLayout(2, 2, 12, 6));
        dataPanel.add(tlLabel);

        dataPanel.add(dollarsLabel);
        dataPanel.add(tlField);
        dataPanel.add(dollarsField);
        JPanel buttonPanel = new JPanel();
        buttonPanel.add(tlButton);
        buttonPanel.add(dollarsButton);
        Container container = this.getContentPane();
        container.add(dataPanel, BorderLayout.CENTER);
        container.add(buttonPanel, BorderLayout.SOUTH);
        tlButton.addActionListener(new TLConverter());
        dollarsButton.addActionListener(new DollarsConverter());
        buttonPanel.add(setRates);
    }

    private class TLConverter implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            try
            {
                String input = tlField.getText();
                double tl = Double.parseDouble(input);
                convertMe.setTL(tl);
                double dollars = convertMe.getDollars();
                dollarsField.setText(String.format("%.2f", dollars));
            }
            catch(Exception ex)
            {
                JOptionPane.showMessageDialog(null, "Please enter the amount that will be converted.");
            }
        }
    }

    private class DollarsConverter implements ActionListener
    {
        public void actionPerformed(ActionEvent e)
        {
            String input = dollarsField.getText();
            double dollars = Double.parseDouble(input);
            convertMe.setDollars(dollars);
            double tl = convertMe.getTL();
            tlField.setText(String.format("%.2f", tl));
        }
    }

    public static void main(String [] args)
    {
        System.out.println("bbb");
        Converter window = new Converter("Para Dönüstürücü"); 
        System.out.println("aaa");
        window.setBounds(30, 30, 300, 300);
        window.setVisible(true);
    /*  Converter theGUI = new Converter();
        theGUI.setTitle("TL to $ or $ to TL Converter");
        theGUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        theGUI.pack();
        theGUI.setVisible(true); */
    }
}

问题在于带有 String 参数的构造函数:subTest.addActionListener(new ActionListener(){...

Answer 1

在默认构造函数中添加对 pack() 的调用。