如何让我的CardLayout UI更新？

Question

我正在尝试使用CardLayout构建游戏的UI，尽管在我的卡片切换方法中使用了revalidate（）和repaint（），但似乎无法使其更新。该程序旨在证明使用CardLayout在JFrame内部切换JPanel的概念，因为如果我可以成功完成该操作，则可以使用其他JPanel重复该过程。不确定该错误是否与线程或更新UI有关。总之，这里是我的代码：

/* 
* To change this license header, choose License Headers in Project Properties. 
* To change this template file, choose Tools | Templates 
* and open the template in the editor. 
*/ 
package nationsapp; 

import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JButton; 
import javax.swing.JLabel; 
import javax.swing.SwingUtilities; 
import java.awt.event.ActionListener; 
import java.awt.event.ActionEvent; 
import java.awt.CardLayout; 
/** 
* 
* @author StephenAHyberger 
*/ 
public abstract class NationsApp { 
    //Initiates the JFrame for the application 
    public static JPanel deck = new JPanel(); 

    //Initiates the CardLayout and its elements for the application 
    public static CardLayout deckShuffle = new CardLayout(); 
    public static String MENUCARD = "MENUCARD"; 
    public static String GAMECARD = "GAMECARD"; 

    //Initiates all the children of the JFrame. Uses CardLayout. 
    public static void init() { 
     //Initiates the JFrame 
     JFrame frame = new JFrame("Nations"); 

     //Initiates the first card and its children 
     JPanel menuPanel = new JPanel(); 
     JButton newGameBtn = new JButton("New Game"); 
     JLabel noteOne = new JLabel("Panel 1"); 

     //Adds the children of the first card into the component heiarchy 
     menuPanel.add(newGameBtn); 
     menuPanel.add(noteOne); 

     //Adds all event listeners on the first card 
     newGameBtn.addActionListener(new NewGame()); 

     //Initiates the second card and its children 
     JPanel gamePanel = new JPanel(); 
     JLabel noteTwo = new JLabel("Panel 2"); 

     //Adds the children of the second card into the component heiarchy 
     gamePanel.add(noteTwo); 

     //Adds the cards to the deck 
     deck.add(menuPanel); 
     deck.add(gamePanel); 

     //Adds the deck to the JFrame 
     frame.add(deck); 

     //Sets up the CardLayout 
     deck.setLayout(new CardLayout()); 
     deckShuffle.addLayoutComponent(frame, MENUCARD); 
     deckShuffle.addLayoutComponent(frame, GAMECARD); 

     //Sets up JFrame behavior and renders the application 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.pack(); 
     frame.setVisible(true); 
    } 
    public static void setWindow(String PLACEHOLDER) { 
     CardLayout cl = (CardLayout)(deck.getLayout()); 
     cl.show(deck, PLACEHOLDER); 
     deck.revalidate(); 
     deck.repaint(); 
    } 
    private static class NewGame implements ActionListener { 
     @Override 
     public void actionPerformed(ActionEvent e) { 
      NationsApp.setWindow(GAMECARD); 
     } 
    } 
    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       NationsApp.init(); 
      } 
     }); 
    } 
} 

非常感谢您的时间，

解决：

我通过应对来自CardLayoutDemo类结构由camickr给出the link进行了广泛的变化（谢谢camickr为你的帮助）。

这里是我的解决方案：

/* 
* To change this license header, choose License Headers in Project Properties. 
* To change this template file, choose Tools | Templates 
* and open the template in the editor. 
*/ 
package nationsapp; 

import java.awt.*; 
import java.awt.event.*; 
import javax.swing.*; 
/** 
* 
* @author StephenAHyberger 
*/ 
public class NationsApp implements ActionListener { 
    //Creates a JPanel to implement a CardLayout 
    JPanel deck; 

    //Creates constraints for the CardLayout 
    final static String MENUCARD = "MENUCARD"; 
    final static String GAMECARD = "GAMECARD"; 

    public void init(Container pane) { 
     //Creates the first card 
     JPanel menuCard = new JPanel(); 
     JButton newGameBtn = new JButton("New Game"); 
     menuCard.add(new JLabel("Panel 1")); 
     menuCard.add(newGameBtn); 

     //Adds EventListeners to the first card 
     newGameBtn.addActionListener(this); 

     //Creates the second card 
     JPanel gameCard = new JPanel(); 
     gameCard.add(new JLabel("Panel 2")); 

     //Creates the deck for the cards 
     deck = new JPanel(new CardLayout()); 
     deck.add(menuCard, MENUCARD); 
     deck.add(gameCard, GAMECARD); 

     pane.add(deck); 
    } 
    private static void render() { 
     //Create and set up the window 
     JFrame frame = new JFrame("Nations"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 

     //Create application class 
     NationsApp app = new NationsApp(); 
     app.init(frame.getContentPane()); 

     //Display the window 
     frame.pack(); 
     frame.setVisible(true); 
    } 
    @Override 
    public void actionPerformed(ActionEvent e) { 
     CardLayout cl = (CardLayout)(deck.getLayout()); 
     cl.show(deck, GAMECARD); 
    } 
    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       render(); 
      } 
     }); 
    } 
} 

Answer 1

类的整体结构是错误的。对此，你不应该使用所有的静态变量和方法。

deckShuffle.addLayoutComponent(frame, MENUCARD); 
    deckShuffle.addLayoutComponent(frame, GAMECARD); 

以上是不需要的。

只需使用add(...)方法将组件添加到面板，就像使用任何其他布局管理器一样。

deck.add(menuPanel, ...); 
    deck.add(gamePanel, ...); 

您需要指定CardLayout使用的约束。

当您尝试交换卡片时，不需要重新验证（）和repaint（）。

我建议你首先阅读关于How to Use CardLayout的Swing教程的部分，以获得一个工作示例。该示例将向您展示如何更好地构建代码以遵循Swing约定。然后，您可以根据需求修改工作示例。