CardLayout 在 Java 中显示空白 JPanel

Question

我搜索了不同的教程并查看了 CardLayout 和 JPanel 的类配置文件，但我似乎无法显示我的窗口。目前它会打开一个具有正确尺寸和标题的框架，但实际容器中没有任何内容。

这是我的代码（P.S. 我知道这是一团糟）

import java.awt.CardLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;
import java.io.IOException;
import javax.sound.sampled.AudioInputStream;
import javax.sound.sampled.AudioSystem;
import javax.sound.sampled.Clip;
import javax.sound.sampled.LineUnavailableException;
import javax.sound.sampled.UnsupportedAudioFileException;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;

public class Casino extends JFrame implements ActionListener {

    private JButton start, settings, scenario, music;


    /**
     * Constructor method
     */

    public Casino(){

        JPanel mainUI, startUI, settingsUI, scenarioUI, blackjackUI, oddorevenUI, tcmUI, overorunderUI, slotsUI;
        JPanel menus = new JPanel(new CardLayout());


        CardLayout GUI = (CardLayout) menus.getLayout();
        mainUI = new JPanel();
        getContentPane().add(mainUI);
        mainUI.setBackground(new Color(53, 9, 9));

        //Background items
        JLabel title = new JLabel(new ImageIcon("title.png"));
        title.setBounds(0,-280,780,700);
        mainUI.add(title);

        JLabel border = new JLabel(new ImageIcon("mainscreenborder.png"));
        border.setBounds(0, 180, 780, 700);
        mainUI.add(border);

        //Main menu buttons
        settings = new JButton();
        ImageIcon s = new ImageIcon("settings-button.png");
        settings.setBounds(320, 200, 122, 63);
        settings.setIcon(s);
        mainUI.add(settings);

        music = new JButton();
        ImageIcon m = new ImageIcon("music-button.png");
        music.setBounds(320, 268, 122, 63);
        music.setBackground(new Color(53, 9, 9));
        music.setIcon(m);
        mainUI.add(music);

        scenario = new JButton();
        ImageIcon sc = new ImageIcon("scenario-button.png");
        scenario.setBounds(320, 336, 122, 63);
        scenario.setBackground(new Color(53, 9, 9));
        scenario.setIcon(sc);
        mainUI.add(scenario);

        start = new JButton();
        ImageIcon st = new ImageIcon("start-button.png");
        start.setBounds(320, 404, 122, 63);
        start.setBackground(new Color(53, 9, 9));
        start.setIcon(st);
        mainUI.add(start);


        menus.add(mainUI, "Main Menu");

        GUI.show(menus, "Main Menu");




        setSize(780, 700);
        setResizable(false);
        setLayout(GUI);
        setTitle("White Lily Casino");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        setVisible(true);
    }

    public void actionPerformed(ActionEvent e){

    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub

        Casino wlc = new Casino();

    }
}

注意：在我使用 Container c 方法而不是使用 JPanel 和 CardLayout 之前，它可以工作。我现在正在尝试将其切换到卡片布局，因为我想使用按钮导航到多个屏幕

Answer 1

尝试将mainUI 添加到JFrame

getContentPane().add(mainUI)

或

add(mainUI)