Java Swing点击btnManga按钮打开指定窗口时弹出空窗口问题

你的代码出现空白窗口的核心原因是：manga类继承了JFrame，但所有可视化组件都被添加到了类内部额外创建的frmAcheterDesLivres对象上，而你点击按钮时调用的是mangaWindow.setVisible(true)，显示的是manga自身继承的空JFrame，而非包含所有内容的frmAcheterDesLivres。

下面提供两种解决方案：

方案一：修改manga类（推荐，符合Swing规范） #

直接使用manga类自身作为主窗口，不再创建额外的JFrame对象，所有组件添加到当前窗口的内容面板中。

修改后的manga.java代码：

package biblio;

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

public class manga extends JFrame {
    private JTable mangatable;

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    manga mangaWindow = new manga();
                    mangaWindow.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }

    public manga() {
        initialize();
    }

    private void initialize() {
        // 直接配置当前manga实例，替代原有的frmAcheterDesLivres
        setTitle("Acheter des Livres");
        setResizable(false);
        getContentPane().setFont(new Font("Yu Gothic Medium", Font.BOLD, 15));
        getContentPane().setBackground(new Color(66, 66, 66));
        setBounds(100, 100, 758, 601);
        // 改为DISPOSE_ON_CLOSE，关闭子窗口不会退出整个程序
        setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
        getContentPane().setLayout(null);
        
        JButton btnNewButton_1_1 = new JButton("");
        btnNewButton_1_1.setIcon(new ImageIcon(manga.class.getResource("/resources/mangas/blackClover.jpg")));
        btnNewButton_1_1.setBounds(31, 46, 125, 125);
        getContentPane().add(btnNewButton_1_1);
        
        JButton btnNewButton_1 = new JButton("");
        btnNewButton_1.setIcon(new ImageIcon(manga.class.getResource("/resources/mangas/chainsawMan.png")));
        btnNewButton_1.setBounds(225, 46, 125, 125);
        getContentPane().add(btnNewButton_1);
        
        JButton btnNewButton_1_2 = new JButton("");
        btnNewButton_1_2.setIcon(new ImageIcon(manga.class.getResource("/resources/mangas/BokuNoHeroAcademia.jpg")));
        btnNewButton_1_2.setBounds(414, 46, 125, 125);
        getContentPane().add(btnNewButton_1_2);
        
        JButton btnNewButton_1_3 = new JButton("");
        btnNewButton_1_3.setIcon(new ImageIcon(manga.class.getResource("/resources/mangas/jujutsuKaisen.jpg")));
        btnNewButton_1_3.setBounds(590, 46, 125, 125);
        getContentPane().add(btnNewButton_1_3);
        
        JLabel lblNewLabel = new JLabel("Black Clover");
        lblNewLabel.setLabelFor(btnNewButton_1_1);
        lblNewLabel.setForeground(new Color(40, 168, 253));
        lblNewLabel.setVerticalAlignment(SwingConstants.TOP);
        lblNewLabel.setHorizontalAlignment(SwingConstants.CENTER);
        lblNewLabel.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblNewLabel.setBounds(31, 185, 125, 34);
        getContentPane().add(lblNewLabel);
        
        JLabel lblMga = new JLabel("40 000 MGA");
        lblMga.setLabelFor(btnNewButton_1_1);
        lblMga.setForeground(new Color(40, 168, 253));
        lblMga.setVerticalAlignment(SwingConstants.TOP);
        lblMga.setHorizontalAlignment(SwingConstants.CENTER);
        lblMga.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblMga.setBounds(31, 210, 125, 34);
        getContentPane().add(lblMga);
        
        JLabel lblChainsawMan = new JLabel("Chainsaw Man");
        lblChainsawMan.setLabelFor(btnNewButton_1);
        lblChainsawMan.setForeground(new Color(40, 168, 253));
        lblChainsawMan.setVerticalAlignment(SwingConstants.TOP);
        lblChainsawMan.setHorizontalAlignment(SwingConstants.CENTER);
        lblChainsawMan.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblChainsawMan.setBounds(235, 181, 125, 34);
        getContentPane().add(lblChainsawMan);
        
        JLabel lblMga_1 = new JLabel("60 000 MGA");
        lblMga_1.setLabelFor(btnNewButton_1);
        lblMga_1.setForeground(new Color(40, 168, 253));
        lblMga_1.setVerticalAlignment(SwingConstants.TOP);
        lblMga_1.setHorizontalAlignment(SwingConstants.CENTER);
        lblMga_1.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblMga_1.setBounds(225, 210, 125, 34);
        getContentPane().add(lblMga_1);
        
        JLabel lblBokuNoHero = new JLabel("Boku no Hero Academia");
        lblBokuNoHero.setLabelFor(btnNewButton_1_2);
        lblBokuNoHero.setVerticalAlignment(SwingConstants.TOP);
        lblBokuNoHero.setHorizontalAlignment(SwingConstants.CENTER);
        lblBokuNoHero.setForeground(new Color(40, 168, 253));
        lblBokuNoHero.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblBokuNoHero.setBounds(414, 181, 125, 34);
        getContentPane().add(lblBokuNoHero);
        
        JLabel lblMga_1_1 = new JLabel("35 000 MGA");
        lblMga_1_1.setLabelFor(btnNewButton_1_2);
        lblMga_1_1.setVerticalAlignment(SwingConstants.TOP);
        lblMga_1_1.setHorizontalAlignment(SwingConstants.CENTER);
        lblMga_1_1.setForeground(new Color(40, 168, 253));
        lblMga_1_1.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblMga_1_1.setBounds(414, 213, 125, 34);
        getContentPane().add(lblMga_1_1);
        
        JLabel lblJujutsuKaisen = new JLabel("Jujutsu Kaisen");
        lblJujutsuKaisen.setLabelFor(btnNewButton_1_3);
        lblJujutsuKaisen.setVerticalAlignment(SwingConstants.TOP);
        lblJujutsuKaisen.setHorizontalAlignment(SwingConstants.CENTER);
        lblJujutsuKaisen.setForeground(new Color(40, 168, 253));
        lblJujutsuKaisen.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblJujutsuKaisen.setBounds(590, 181, 125, 34);
        getContentPane().add(lblJujutsuKaisen);
        
        JLabel lblMga_1_1_1 = new JLabel("23 000 MGA");
        lblMga_1_1_1.setLabelFor(btnNewButton_1_3);
        lblMga_1_1_1.setVerticalAlignment(SwingConstants.TOP);
        lblMga_1_1_1.setHorizontalAlignment(SwingConstants.CENTER);
        lblMga_1_1_1.setForeground(new Color(40, 168, 253));
        lblMga_1_1_1.setFont(new Font("Yu Gothic Medium", Font.ITALIC, 14));
        lblMga_1_1_1.setBounds(590, 213, 125, 34);
        getContentPane().add(lblMga_1_1_1);
        
        JLabel lblNewLabel_1 = new JLabel("Votre Panier de Mangas:");
        lblNewLabel_1.setFont(new Font("Yu Gothic UI Semibold", Font.PLAIN, 20));
        lblNewLabel_1.setForeground(new Color(38, 217, 255));
        lblNewLabel_1.setBounds(257, 291, 282, 34);
        getContentPane().add(lblNewLabel_1);
        
        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setBounds(61, 335, 641, 158);
        getContentPane().add(scrollPane);
        
        mangatable = new JTable();
        scrollPane.setViewportView(mangatable);
        mangatable.setBackground(new Color(49, 49, 49));
        mangatable.setForeground(new Color(38, 217, 255));
    }
}

关键修改点：

1. 删除了冗余的private JFrame frmAcheterDesLivres;字段
2. 将所有frmAcheterDesLivres.xxx()调用替换为当前类的xxx()方法
3. 把关闭操作改为DISPOSE_ON_CLOSE，避免关闭子窗口时退出整个程序

方案二：修改按钮事件监听（不推荐，破坏封装） #

如果不想改动manga类结构，可将frmAcheterDesLivres改为public字段，然后在按钮点击时显示该窗口：

1. 修改manga.java的字段定义：

public JFrame frmAcheterDesLivres;

2. 修改principal.java中的按钮监听代码：

btnManga.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        manga mangaWindow = new manga();
        mangaWindow.frmAcheterDesLivres.setVisible(true);
    }
});

额外建议 #

1. Java类名需遵守大驼峰规范，principal和manga应改为Principal和Manga
2. 尽量避免使用null布局，推荐使用BorderLayout、GridBagLayout等布局管理器，提升界面兼容性

内容的提问来源于stack exchange，提问作者Stract