2

我知道这与我的设置方式和动作监听器没有正确设置到框架或其他什么有关，但我就是无法听到它。如果有人能指出我正确的方向，我将不胜感激。对不起菜鸟问题。

这是我所拥有的：

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

public class Main implements ActionListener {

    JPanel cardHolder;
    public static final String HOME_CARD = "Home";
    public static final String BLUE_PANEL = "Blue Panel";
    public static final String RED_PANEL = "Red Panel";
    public static final String ORANGE_PANEL = "Orange Panel";

    public static JButton home = new JButton("Home");
    public static JButton bluePanel = new JButton("Blue Card");
    public static JButton redPanel = new JButton("Red Panel");
    public static JButton orangePanel = new JButton("Orange Panel");

    public static JPanel createCardHolderPanel() {
        JPanel cardHolder = new JPanel(new CardLayout());
        cardHolder.setBorder(BorderFactory.createTitledBorder("Card Holder Panel"));

        cardHolder.add(createHomeCard(), HOME_CARD);
        cardHolder.add(createBluePanel(), BLUE_PANEL);
        cardHolder.add(createRedPanel(), RED_PANEL);
        cardHolder.add(createOrangePanel(), ORANGE_PANEL);

        return cardHolder;
    }

    private static JPanel createOrangePanel() {
        JPanel orangePanel = new JPanel();

        orangePanel.setBackground(Color.orange);
        return orangePanel;
    }

    private static Component createRedPanel() {
        JPanel redPanel = new JPanel();

        redPanel.setBackground(Color.red);
        return redPanel;
    }

    private static Component createBluePanel() {
        JPanel bluePanel = new JPanel();

        bluePanel.setBackground(Color.blue);
        return bluePanel;
    }

    private static Component createHomeCard() {
        JPanel homePanel = new JPanel();

        homePanel.setBackground(Color.GRAY);
        return homePanel;
    }

    public static JPanel createButtonPanel() {
        JPanel buttonPanel = new JPanel(new GridLayout(4, 0, 5, 5));
        buttonPanel.setBorder(BorderFactory.createTitledBorder("Button Panel"));

        buttonPanel.add(home);
        buttonPanel.add(bluePanel);
        buttonPanel.add(redPanel);
        buttonPanel.add(orangePanel);

        return buttonPanel;
    }

    public static JPanel createContentPane() {
        JPanel contentPane = new JPanel(new BorderLayout());

        contentPane.setBorder(BorderFactory.createTitledBorder("Main Content Pane"));
        contentPane.setBackground(Color.WHITE);
        contentPane.setPreferredSize(new Dimension(499, 288));

        contentPane.add(createButtonPanel(), BorderLayout.WEST);
        contentPane.add(createCardHolderPanel(),BorderLayout.CENTER);

        return contentPane;
    }

    public static JMenuBar createMenuBar() {
        JMenuBar menuBar = new JMenuBar();

        JMenu file = new JMenu("File");
        JMenu users = new JMenu("Users");
        JMenu options = new JMenu("Options");
        JMenu help = new JMenu("Help");

        menuBar.add(file);
        menuBar.add(users);
        menuBar.add(options);
        menuBar.add(help);

        return menuBar;
    }

    public static void createAndShowGUI() {
        JFrame frame = new JFrame("Simple CardLayout Program");
        frame.setContentPane(createContentPane());
        frame.setJMenuBar(createMenuBar());
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }

    @Override
    public void actionPerformed(ActionEvent e) {

        if (e.getSource() == home) {
            CardLayout cardLayout = (CardLayout) (cardHolder.getLayout());
            cardLayout.show(cardHolder, HOME_CARD);
        }

        if (e.getSource() == bluePanel) {
            CardLayout cardLayout = (CardLayout) (cardHolder.getLayout());
            cardLayout.show(cardHolder, BLUE_PANEL);
        }

        if (e.getSource() == redPanel) {
            CardLayout cardLayout = (CardLayout) (cardHolder.getLayout());
            cardLayout.show(cardHolder, RED_PANEL);
        }

        if (e.getSource() == orangePanel) {
            CardLayout cardLayout = (CardLayout) (cardHolder.getLayout());
            cardLayout.show(cardHolder, ORANGE_PANEL);
        }
    }
}
4

2 回答 2

3

其他人建议听按钮；此外：

  • 首选与使用一致的最低可访问性，例如，private而不是public.
  • 不要什么都做static。
  • static用于整个类中使用的不可变常量。
  • 对内容使用类变量而不是静态成员。
  • 不要重复你自己，例如cardLayout在你的actionPerformed)().

  • 对每种颜色使用参数而不是单独的方法，例如

    private JPanel createColorPanel(Color color) {...}

修改后的代码：

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

public class Main implements ActionListener {

    private static final String HOME_CARD = "Home";
    private static final String BLUE_PANEL = "Blue Panel";
    private static final String RED_PANEL = "Red Panel";
    private static final String ORANGE_PANEL = "Orange Panel";
    private JPanel cardHolder;
    private JButton homeButton = new JButton("Home");
    private JButton blueButton = new JButton("Blue Card");
    private JButton redButton = new JButton("Red Panel");
    private JButton orangeButton = new JButton("Orange Panel");

    public JPanel createCardHolderPanel() {
        cardHolder = new JPanel(new CardLayout());
        cardHolder.setBorder(BorderFactory.createTitledBorder("Card Holder Panel"));
        cardHolder.add(createColorPanel(Color.gray), HOME_CARD);
        cardHolder.add(createColorPanel(Color.blue), BLUE_PANEL);
        cardHolder.add(createColorPanel(Color.red), RED_PANEL);
        cardHolder.add(createColorPanel(Color.orange), ORANGE_PANEL);

        return cardHolder;
    }

    private JPanel createColorPanel(Color color) {
        JPanel panel = new JPanel();
        panel.setBackground(color);
        return panel;
    }

    public JPanel createButtonPanel() {
        JPanel buttonPanel = new JPanel(new GridLayout(4, 0, 5, 5));
        buttonPanel.setBorder(BorderFactory.createTitledBorder("Button Panel"));
        buttonPanel.add(homeButton);
        buttonPanel.add(blueButton);
        buttonPanel.add(redButton);
        buttonPanel.add(orangeButton);
        homeButton.addActionListener(this);
        blueButton.addActionListener(this);
        redButton.addActionListener(this);
        orangeButton.addActionListener(this);
        return buttonPanel;
    }

    public JPanel createContentPane() {
        JPanel panel = new JPanel(new BorderLayout());
        panel.setBorder(BorderFactory.createTitledBorder("Main Content Pane"));
        panel.setBackground(Color.WHITE);
        panel.setPreferredSize(new Dimension(499, 288));
        panel.add(createButtonPanel(), BorderLayout.WEST);
        panel.add(createCardHolderPanel(), BorderLayout.CENTER);
        return panel;
    }

    public JMenuBar createMenuBar() {
        JMenuBar menuBar = new JMenuBar();
        JMenu file = new JMenu("File");
        JMenu users = new JMenu("Users");
        JMenu options = new JMenu("Options");
        JMenu help = new JMenu("Help");
        menuBar.add(file);
        menuBar.add(users);
        menuBar.add(options);
        menuBar.add(help);
        return menuBar;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        CardLayout cardLayout = (CardLayout) (cardHolder.getLayout());
        if (e.getSource() == homeButton) {
            cardLayout.show(cardHolder, HOME_CARD);
        }
        if (e.getSource() == blueButton) {
            cardLayout.show(cardHolder, BLUE_PANEL);
        }
        if (e.getSource() == redButton) {
            cardLayout.show(cardHolder, RED_PANEL);
        }
        if (e.getSource() == orangeButton) {
            cardLayout.show(cardHolder, ORANGE_PANEL);
        }
    }

    public static void createAndShowGUI() {
        JFrame frame = new JFrame("Simple CardLayout Program");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Main main = new Main();
        frame.setJMenuBar(main.createMenuBar());
        frame.add(main.createContentPane());
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {

            @Override
            public void run() {
                createAndShowGUI();
            }
        });
    }
}
于 2012-05-29T20:15:57.050 回答
1

您还没有为任何按钮设置动作侦听器。实现接口的 actionPerformed 方法不会自动为按钮设置动作监听器。您必须调用 addActionListener 方法，在您的情况下，该方法如下所示，因为您的类实现了 ActionListener 接口。

public static JButton home = new JButton("Home").addActionListener(this); 
public static JButton bluePanel = new JButton("Blue Card").addActionListener(this); 
public static JButton redPanel = new JButton("Red Panel").addActionListener(this); 
public static JButton orangePanel = new JButton("Orange Panel").addActionListener(this);
于 2012-05-29T18:45:20.217 回答