How do I use CardLayout for my Java Program for Login and Menu Items

Question

I am creating a \"Store\" program that basically can allow an employee to log in with a username and password I provide. After logging in, the employee can then see a \"main

Answer 1

1. Stop using null layouts, seriously, this is the source of more problems then just about anything else with Swing
2. When adding components to a panel using CardLayout, each panel MUST have a name
3. In your actionPerformed method, this is not how CardLayout works. To start with, you're creating a new instance of CardLayout, which contains NO components, so how did you expect it to be able to suddenly figure out what to switch to? When using CardLayout#show, the component reference is the parent component that that is begin manged by the CardLayout

Updated with example

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.List;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class MyCardLayout {

    public static void main(String[] args) {
        new MyCardLayout();
    }

    public MyCardLayout() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        private JPanel mainPane;
        private JPanel navPane;
        private List pages;
        private int currentPage;

        public TestPane() {
            pages = new ArrayList<>(25);
            setLayout(new BorderLayout());

            mainPane = new JPanel(new CardLayout());
            navPane = new JPanel();

            for (int index = 0; index < 10; index++) {
                addPageTo(mainPane, "Page" + index, new JLabel("Page " + index, JLabel.CENTER));
            }

            JButton btnPrev = new JButton("<<");
            JButton btnNext = new JButton(">>");

            navPane.add(btnPrev);
            navPane.add(btnNext);

            btnPrev.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    setCurrentPage(getCurrentPage() - 1);
                }
            });
            btnNext.addActionListener(new ActionListener() {
                @Override
                public void actionPerformed(ActionEvent e) {
                    setCurrentPage(getCurrentPage() + 1);
                }
            });

            add(mainPane);
            add(navPane, BorderLayout.SOUTH);

            setCurrentPage(0);
        }

        public int getCurrentPage() {
            return currentPage;
        }

        protected void setCurrentPage(int page) {
            if (pages.size() > 0) {
                if (page < 0) {
                    page = pages.size() - 1;
                } else if (page >= pages.size()) {
                    page = 0;
                }

                currentPage = page;
                CardLayout layout = (CardLayout)mainPane.getLayout();
                layout.show(mainPane, pages.get(currentPage));
            }
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

        protected void addPageTo(JPanel pane, String name, Component comp) {
            pages.add(name);
            pane.add(comp, name);
        }
    }
}