JFrame 組件添加后不顯示

Question

我目前正在 Java 上使用 class，我決定嘗試制作自己的程序。 我在制作一個簡單的空閑點擊游戲時遇到了問題，我不確定我做錯了什么。 當我運行程序時，我一直試圖打開一個菜單，但由於某種原因，我添加到 JFrame 的組件沒有出現。

我已經嘗試重新組織我的代碼，並且我已經對解決方案進行了一些環顧，但是所有問題都通過setVisible(true);解決了。 在將所有組件添加到框架之后，我已經完成了。

這是我的代碼：

import java.awt.*;
import java.awt.event.*;

public class Main extends JFrame implements ActionListener{
    int counter = 10000;
    int autoClickerCost = 100;
    int autoClickerDelay = 1000;
    int autoClickerCount = 0;
    boolean hasAutoClicker;
    JLabel counterField, autoClickerSplash, invText, autoClickerCountTxt;
    JButton countUp, autoClickerUpgrade;
    JPanel clickerPanel, upgrades, shop, inv, mainPanel;
    SpringLayout overallLayout, upgradesLayout, clickerPanelLayout, shopLayout, invLayout, mainPanelLayout;
    Timer autoClickerTimer;

    public Main() {
        super("Idle clicker");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        Container pane = getContentPane();
        overallLayout = new SpringLayout();
        pane.setLayout(overallLayout);
        
        inv = new JPanel();
        invLayout = new SpringLayout();
        inv.setLayout(invLayout);
        
        mainPanel = new JPanel();
        mainPanelLayout = new SpringLayout();
        mainPanel.setLayout(mainPanelLayout);
        
        clickerPanel = new JPanel();
        clickerPanelLayout = new SpringLayout();
        clickerPanel.setLayout(clickerPanelLayout);
        
        upgrades = new JPanel();
        upgradesLayout = new SpringLayout();
        upgrades.setLayout(upgradesLayout);
        
        invText = new JLabel("Inventory:");
        invText.setFont(invText.getFont().deriveFont(24.0f));
        
        counterField = new JLabel("Current Clicks: " + counter);
        counterField.setFont(counterField.getFont().deriveFont(24.0f));
        
        autoClickerCountTxt = new JLabel("Autoclickers: " + autoClickerCount);
        autoClickerCountTxt.setFont(autoClickerCountTxt.getFont().deriveFont(12.0f));
        
        countUp = new JButton("Click Me");
        countUp.setFont(countUp.getFont().deriveFont (12.0f));
        countUp.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                counter++;
                counterField.setText("Current Clicks: " + counter);
                if(counter > 50 && hasAutoClicker == false) {
                    upgrades.add(autoClickerUpgrade);
                    upgradesLayout.putConstraint(SpringLayout.NORTH, autoClickerUpgrade, 5, SpringLayout.NORTH, upgrades);
                    upgradesLayout.putConstraint(SpringLayout.WEST, autoClickerUpgrade, 5, SpringLayout.WEST, upgrades);
                }
                if(hasAutoClicker == true) {
                    
                }
            }
            
        });
        autoClickerUpgrade = new JButton("Autoclicker: " + autoClickerCost + " clicks");
        autoClickerUpgrade.setFont (countUp.getFont ().deriveFont (12.0f));
        autoClickerUpgrade.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                if(counter >= autoClickerCost && hasAutoClicker == false) {
                    autoClickerDelay = 1000;
                    ActionListener taskPerformer = new ActionListener() {
                        public void actionPerformed(ActionEvent evt) {
                            counter = counter + 1;
                            counterField.setText("Current Clicks: " + counter);
                        }
                    };
                    autoClickerTimer = new Timer(autoClickerDelay, taskPerformer);
                    autoClickerTimer.start();
                    hasAutoClicker = true;
                    autoClickerCount = autoClickerCount + 1;
                    autoClickerCountTxt.setText("Autoclickers: " + autoClickerCount);
                    counter = counter - autoClickerCost;
                    counterField.setText("Current Clicks: " + counter);
                    autoClickerCost = (int) Math.round(autoClickerCost * 1.25);
                    autoClickerUpgrade.setText("Autoclicker: " + autoClickerCost + " clicks");
                }
                else if(counter >= autoClickerCost && hasAutoClicker == true) {
                    if(autoClickerDelay > 1) {
                        autoClickerCount = autoClickerCount + 1;
                        autoClickerCountTxt.setText("Autoclickers: " + autoClickerCount);
                        autoClickerDelay = (int) Math.ceil(1000 / autoClickerCount);
                        autoClickerTimer.setDelay(autoClickerDelay);
                        hasAutoClicker = true;
                        counter = counter - autoClickerCost;
                        counterField.setText("Current Clicks: " + counter);
                        autoClickerCost = (int) Math.round(autoClickerCost * 1.5);
                        autoClickerUpgrade.setText("Autoclicker: " + autoClickerCost + " clicks");
                    }
                }
            }
        });
        
        inv.add(invText);
        invLayout.putConstraint(SpringLayout.WEST, invText, 5, SpringLayout.WEST, inv);
        invLayout.putConstraint(SpringLayout.NORTH, invText, 5, SpringLayout.NORTH, inv);
        
        inv.add(autoClickerCountTxt);
        invLayout.putConstraint(SpringLayout.WEST, autoClickerCountTxt, 5, SpringLayout.WEST, inv);
        invLayout.putConstraint(SpringLayout.NORTH, autoClickerCountTxt, 10, SpringLayout.SOUTH, invText);
        
        clickerPanel.add(counterField);
        clickerPanelLayout.putConstraint(SpringLayout.WEST, counterField, 5, SpringLayout.WEST, clickerPanel);
        clickerPanelLayout.putConstraint(SpringLayout.NORTH, counterField, 5, SpringLayout.NORTH, clickerPanel);
        
        clickerPanel.add(countUp);
        clickerPanelLayout.putConstraint(SpringLayout.NORTH, countUp, 5, SpringLayout.SOUTH, counterField);
        clickerPanelLayout.putConstraint(SpringLayout.WEST, countUp, 5, SpringLayout.WEST, clickerPanel);
        
        mainPanel.add(clickerPanel);
        mainPanelLayout.putConstraint(SpringLayout.NORTH, clickerPanel, 5, SpringLayout.NORTH, mainPanel);
        mainPanelLayout.putConstraint(SpringLayout.WEST, clickerPanel, 5, SpringLayout.WEST, mainPanel);
        
        mainPanel.add(upgrades);
        mainPanelLayout.putConstraint(SpringLayout.NORTH, upgrades, 5, SpringLayout.NORTH, mainPanel);
        mainPanelLayout.putConstraint(SpringLayout.WEST, upgrades, 5, SpringLayout.SOUTH, clickerPanel);
        
        pane.add(inv);
        overallLayout.putConstraint(SpringLayout.NORTH, inv, 5, SpringLayout.NORTH, pane);
        overallLayout.putConstraint(SpringLayout.WEST, inv, 5, SpringLayout.WEST, pane);
        
        pane.add(mainPanel);
        overallLayout.putConstraint(SpringLayout.NORTH, mainPanel, 5, SpringLayout.SOUTH, inv);
        overallLayout.putConstraint(SpringLayout.WEST, mainPanel, 5, SpringLayout.WEST, pane);
        
        setContentPane(pane);
        pack();
        setVisible(true);
    }
    
    public void actionPerformed(ActionEvent event) {
        
    }
    
    public static void main(String[] args) {
        Main example = new Main();
    }
}

我覺得我錯過了一些非常明顯的東西，或者可能有一個我還不知道的關鍵概念。 如果有人可以將我推向正確的方向，那就太好了！

Answer 1

正如我的評論中提到的，一個常見問題的簡單答案：

parent.revalidate(); parent.repaint();

但我想和你一起更進一步。 Swing 被構建為單線程。 這意味着在您的 setVisible 調用之后，所有添加/更改/刪除 JComponents 都應該在 Swing / EventDispatchingThread 上完成。 你這樣做的方式（通常）是創建可運行文件並使用 SwingUtilities.invokeLater

SwingUtilities.invokeLater(new Runnable() {
  public void run() {
    parentX.add(childY);
    parentX.revalidate();
    parentX.repaint();
  }
}

這樣可以確保這些操作是線程安全的，並且在 EDT 繪制組件時不會發生。