CardLayout（swing）在按钮上带有动作侦听器？

Question

我一直在尝试通过按钮上的动作侦听器找出 CardLayout （就像 - 从加载页面开始 - 并在按钮上单击切换到不同的“卡片”

我的代码现在甚至无法运行我不完全确定为什么 - 我能找到的大多数实现都使用 ItemListeners 和 Combo Boxes

我做的基本流程是创建一个master JPanel，但是我的卡片JPanel放到master JPanel上，但是我不同的卡片放到cards JPanel中，然后把master JPanel添加到frame中显示...

另外，对于我的一张卡片，我只需要显示一张图片 - 我之前通过创建一个新的弹出窗口来实现这一点，但是能够切换框架以显示它会很好......我不知道为什么我想不通

这是我的代码：

import java.awt.*;

/** 
 * Game
 * Main class that specifies the frame and widgets of the GUI
 */
public class Game implements Runnable {
public void run(){

    final String ON_OPEN = "Welcome!"; //Opening frame
    final String GAME = "Play!"; // Game Frame
    final String STATS = "Stats"; // Post-Game Stat Frame
    final String HELP = "Help"; //tutorial frame
    JPanel cards = new JPanel(); 
    JPanel master; // a panel for the card layout

    final JFrame frame = new JFrame(ON_OPEN);
    frame.setLocation(500,200);

    //Create the master layout for the program
    master = (JPanel) frame.getContentPane();
    master.setLayout(new BorderLayout()); // creating master layout

    //Create panel for all the cards in CardLayout
    final CardLayout cLay = new CardLayout();
    cards.setLayout(cLay);


    // all the cards
    final JPanel help = new JPanel();
    final JPanel stats = new JPanel();
    final JPanel game = new JPanel (new BorderLayout());
    final JPanel open = new JPanel (new FlowLayout());


    // setting up ON_OPEN layout - uses JPanel open

    final ImageIcon img = new ImageIcon("Instructions.png", "My Instructions..."); // the image I want shown under HELP card
    final JButton info = new JButton("Help");
    info.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
    //      cLay.show(help, HELP);     // WHAT I NORMALLY SHOULD BE DOING, RATHER JUST MAKE A NEW FRAME FOR THIS THOUGH
    //      frame.pack();

            final JFrame infoFrame = new JFrame("Tutorial");
            infoFrame.setLocation(500,50);
            JLabel tutorialImg = new JLabel(img);
    //      int w = img.getIconWidth();
        //  int h = img.getIconHeight();
            //infoFrame.setSize(w, h);
            infoFrame.pack();
            infoFrame.add(tutorialImg);
            infoFrame.setVisible(true);
        }
    });
    open.add(info); // the open-tutorial button



    //Add them to the cards JPanel
    cards.add(open, ON_OPEN);
    cards.add(help, HELP);
    cards.add(stats, STATS);
    cards.add(game, GAME);

    //Add the cards panel to the Master layout panel
    master.add(cards);


    // This code is all commented out because I'm not sure what I'm doing here...
//  frame.add(cards);
//  cLay.show(cards, ON_OPEN);

//  frame.add(open, BorderLayout.CENTER);

    // Main playing area - I want this to be shown in the GAME card...

    GridLayout tileGrid = new GridLayout(4,4);
    final JPanel grid = new JPanel(tileGrid);
      //    game.add(grid, BorderLayout.CENTER);

    //      grid.setLayout(tileGrid);
    //  frame.add(grid, BorderLayout.CENTER);


    // Input - holds typing box
    //        final JPanel status_panel = new JPanel();

    //  frame.add(cards, BorderLayout.CENTER);


//  frame.add(open, BorderLayout.CENTER);

    final JTextField typingArea = new JTextField();
    typingArea.setFocusTraversalKeysEnabled(false);
    typingArea.setEditable(true);
    typingArea.setFocusable(true);
    typingArea.requestFocus();


    frame.add(typingArea, BorderLayout.SOUTH);
    typingArea.addKeyListener(new KeyAdapter() {
        public void keyPressed (KeyEvent e) {
            if (e.getKeyCode() == KeyEvent.VK_ENTER) { // enter key is pressed
                String userWord = typingArea.getText().toLowerCase();
                typingArea.setText("");

            }
        }
    });


    final JLabel status = new JLabel("Running...");
    //        status_panel.add(status);

    // Reset button
    final JPanel control_panel = new JPanel();
    frame.add(control_panel, BorderLayout.NORTH);



    ]

    // Put the frame on the screen
    frame.pack();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setVisible(true);
}


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

}

Answer 1

问题：

• 您的代码无法为我们编译，因为我们没有 JLetterField 类。
• 您正在尝试将 JFrame 的 contentPane 添加回自身，并导致异常且没有意义。

---

编辑 1：

• 您的最新代码显示您将所有内容都放入一个非常大的 run() 方法中，但这样做，您失去了很多，却一无所获。
• 我建议去掉 Runnable 接口，不需要它，并创建一个真正符合 OOP 的类，该类具有私有字段以及公共和私有方法。
• 您的 actionPerformed 方法显示未尝试更改 CardLayout 的显示卡片。
• 我建议你去掉显示新窗口的代码，并尝试在那里放置换卡代码。
• 制作您的 CardLayout 和该类的卡片显示 JPanel 字段，以便其他方法可以访问它们并调用它们的方法。

---

编辑 2：

例如，以下代码显示了使用 3 个 JButton 交换卡片。一张获得上一张卡片，一张获得下一张卡片，一张展示如何获得一张特定卡片（这里是第二张）：

import java.awt.BorderLayout;
import java.awt.CardLayout;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;

import javax.swing.*;

@SuppressWarnings("serial")
public class CardLayoutEg extends JPanel {
   private static final String[] CARD_LABELS = { "one", "two", "three", "four",
         "five", "six", "seven", "eight", "nine", "ten" };
   private static final int PREF_W = 400;
   private static final int PREF_H = PREF_W;
   private CardLayout cardlayout = new CardLayout();
   private JPanel cardHolder = new JPanel(cardlayout);
   private Action[] actions = { new ShowPreviousAction(), new ShowNextAction(),
         new ShowTwoCardAction() };

   public CardLayoutEg() {
      for (String cardLabelText : CARD_LABELS) {
         JLabel cardLabel = new JLabel(cardLabelText, SwingConstants.CENTER);
         cardHolder.add(cardLabel, cardLabelText);
      }

      JPanel btnPanel = new JPanel(new GridLayout(1, 0, 5, 0));
      for (Action action : actions) {
         btnPanel.add(new JButton(action));
      }

      setLayout(new BorderLayout());
      add(cardHolder, BorderLayout.CENTER);
      add(btnPanel, BorderLayout.SOUTH);
   }

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

   private class ShowPreviousAction extends AbstractAction {
      public ShowPreviousAction() {
         super("Previous");
      }

      @Override
      public void actionPerformed(ActionEvent e) {
         cardlayout.previous(cardHolder);
      }
   }

   private class ShowNextAction extends AbstractAction {
      public ShowNextAction() {
         super("Next");
      }

      @Override
      public void actionPerformed(ActionEvent e) {
         cardlayout.next(cardHolder);
      }
   }

   private class ShowTwoCardAction extends AbstractAction {
      public ShowTwoCardAction() {
         super("Show Two");
      }

      @Override
      public void actionPerformed(ActionEvent e) {
         cardlayout.show(cardHolder, CARD_LABELS[1]);
      }
   }

   private static void createAndShowGui() {
      CardLayoutEg mainPanel = new CardLayoutEg();

      JFrame frame = new JFrame("CardLayout Example");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(mainPanel);
      frame.pack();
      frame.setLocationByPlatform(true);
      frame.setVisible(true);
   }

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