JButton不产生输出 - 剪刀石头布游戏(GUI, Java)

Question

我有一个学校的任务，我将创建一个石头，纸，剪刀的游戏与计算机。游戏应该能够在游戏进行的过程中记录分数。

代码编译成功，但当我运行游戏时，"石头"、"纸 "和 "剪刀 "的按钮没有任何效果，尽管计算机能够成功地选择其中一个。我在游戏中加入了 addActionListener, setActionCommand 并使之成为要么是石头剪刀布的形象变化，要么是石头剪刀布的形象变化。actionPerformed 通过if语句，将Icon设置为所选对象的图像。

理想情况下，计算机和用户都应该选择（计算机通过Math.random），然后将变量 results 应该说用户是否赢了。

我翻看了代码，也在网上找了解决方案，在修正了一些小错误后，同样的问题普遍存在：石头、纸和剪刀的JButton在用户按下后也不显示任何结果。是我的按钮缺失了一个方面还是我漏掉了什么明显的东西？

这是我的代码。

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

public class attempt5 extends JPanel implements ActionListener {

    JButton rock, paper, scissors, cont;
    JLabel YOURscore2, COMPscore2, results, YOURpic, COMPpic;
    int yours = 0;
    int theirs = 0;

    public static void main(String args[]) { //main
        attempt5 content = new attempt5();

        JFrame window = new JFrame("Rock, Paper Scissors");
        window.setContentPane(content);
        window.setSize(600, 1000);
        window.setLocation(100, 100);
        window.setVisible(true);

    } //end main


    public attempt5() { //constructor
        JLabel title = new JLabel("Rock, Paper, Scissors");
        title.setFont(new Font("Arial", Font.BOLD, 50));
        title.setForeground(Color.red);
        JLabel pick = new JLabel("Pick one:");
        pick.setFont(new Font("Arial", Font.ITALIC, 50));

        rock = new JButton("ROCK");
        rock.addActionListener(this);
        rock.setActionCommand("rock");
        paper = new JButton("PAPER");
        paper.addActionListener(this);
        paper.setActionCommand("paper");
        scissors = new JButton("SCISSORS");
        scissors.addActionListener(this);
        scissors.setActionCommand("scissors");

        JLabel picture = new JLabel(createImageIcon("rockpaperscissors.png"));

        cont = new JButton("Continue");
        cont.setPreferredSize(new Dimension(350, 48));
        cont.addActionListener(this);
        cont.setActionCommand("continue");

        JLabel YOURchoice = new JLabel("Your choice:");
        YOURpic = new JLabel("--");
        JLabel COMPchoice = new JLabel("Computer's choice:");
        COMPpic = new JLabel("--");

        results = new JLabel("--");
        results.setFont(new Font("Arial", Font.BOLD, 40));

        JLabel YOURscore = new JLabel("Your score: ");
        pick.setFont(new Font("Arial", Font.ITALIC, 35));
        YOURscore2 = new JLabel("--");
        JLabel COMPscore = new JLabel("Computer's score: ");
        pick.setFont(new Font("Arial", Font.ITALIC, 35));
        COMPscore2 = new JLabel("--");

        add(title);
        add(picture);
        add(pick);
        add(rock);
        add(paper);
        add(scissors);
        add(cont);
        add(YOURchoice);
        add(YOURpic);
        add(COMPchoice);
        add(COMPpic);
        add(results);
        add(YOURscore);
        add(YOURscore2);
        add(COMPscore);
        add(COMPscore2);

    } //end constructor

    public void actionPerformed(ActionEvent e) {
        int n = (int)(Math.random() * 3 + 1);

        if (e.getActionCommand().equals("continue")) {
            {
                if (n == 1) {
                    COMPpic.setIcon(createImageIcon("rock.png"));
                } else if (n == 2) {
                    COMPpic.setIcon(createImageIcon("newspaper.png"));
                } else {
                    COMPpic.setIcon(createImageIcon("scissors.png"));
                }
            }


            if (e.getActionCommand().equals("rock")) {
                YOURpic.setIcon(createImageIcon("rock.png"));
                if (n == 1)
                    results.setText("Tie");
                else if (n == 2) {
                    results.setText("Computer wins");
                    theirs++;
                } else if (n == 3) {
                    results.setText("You win");
                    yours++;
                }

            } else if (e.getActionCommand().equals("paper")) {
                YOURpic.setIcon(createImageIcon("newspaper.png"));
                if (n == 1) {
                    results.setText("You win");
                    yours++;
                } else if (n == 2)
                    results.setText("Tie");
                else if (n == 3) {
                    results.setText("You loose");
                    theirs++;
                }
            } else if (e.getActionCommand().equals("scissors")) {
                YOURpic.setIcon(createImageIcon("scissors.png"));
                if (n == 1) {
                    results.setText("You loose");
                    theirs++;
                } else if (n == 2) {
                    results.setText("You win");
                    yours++;
                } else if (n == 3)
                    results.setText("Computer wins");
            }

            YOURscore2.setText(" " + yours);
            COMPscore2.setText(" " + theirs);
        }
    }

    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = attempt5.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }
} //end main

Answer 1

我不确定我是否发现了所有的问题。

我不知道是什么 Continue 按钮应该做的。

总之，这是我修复的GUI。

下面是我对代码的主要修改。

1. 我在 事件派遣线程 通过将Swing组件的创建和执行放在一个对 SwingUtilities invokeLater 方法。

2. 我用的是 周转式布局管理器 来定位各种Swing组件。 这样就可以调整JFrame的大小。

3. 我读取了一次文件图像，并将其保存为 ImageIcons. 这样一来，游戏就不用一直从资源文件夹中读取图片了。

这是修改后的代码。

import java.awt.Color;
import java.awt.Component;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;

public class Attempt5 extends JPanel implements ActionListener {

    private static final long serialVersionUID = 1L;

    private ImageIcon rockIcon;
    private ImageIcon paperIcon;
    private ImageIcon scissorsIcon;

    private JButton rock, paper, scissors, cont;
    private JLabel YOURscore2, COMPscore2, results;
    private JLabel YOURpic, COMPpic;
    private int yours = 0;
    private int theirs = 0;

    public static void main(String args[]) { // main
        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                Attempt5 content = new Attempt5();

                JFrame window = new JFrame(
                        "Rock, Paper Scissors");
                window.setDefaultCloseOperation(
                        JFrame.EXIT_ON_CLOSE);
                window.setContentPane(content);
                window.pack();
                window.setLocationByPlatform(true);
                window.setVisible(true);
            }   
        });
    } // end main

    public Attempt5() { // constructor
        this.rockIcon = createImageIcon("rock.png");
        this.paperIcon = createImageIcon("newspaper.png");
        this.scissorsIcon = createImageIcon("scissors.png");

        setLayout(new GridBagLayout());

        // top, left, bottom, right
        Insets topInsets = new Insets(10, 10, 10, 10);
        Insets insets = new Insets(0, 10, 10, 10);
        Insets rightInsets = new Insets(0, 0, 10, 10);

        int gridy = 0;

        JLabel title = new JLabel("Rock, Paper, Scissors");
        title.setHorizontalAlignment(JLabel.CENTER);
        title.setFont(new Font("Arial", Font.BOLD, 50));
        title.setForeground(Color.red);
        addComponent(this, title, 0, gridy++, 4, 1, 
                topInsets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);


        JLabel pick = new JLabel("Pick one:");
        pick.setFont(new Font("Arial", Font.ITALIC, 50));
        addComponent(this, pick, 0, gridy, 1, 1, 
                insets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        JPanel buttonPanel = new JPanel();
        buttonPanel.setLayout(new GridLayout(0, 3, 10, 10));

        rock = new JButton("ROCK");
        rock.setFont(new Font("Arial", Font.PLAIN, 20));
        rock.addActionListener(this);
        rock.setActionCommand("rock");
        buttonPanel.add(rock);

        paper = new JButton("PAPER");
        paper.setFont(new Font("Arial", Font.PLAIN, 20));
        paper.addActionListener(this);
        paper.setActionCommand("paper");
        buttonPanel.add(paper);

        scissors = new JButton("SCISSORS");
        scissors.setFont(new Font("Arial", Font.PLAIN, 20));
        scissors.addActionListener(this);
        scissors.setActionCommand("scissors");
        buttonPanel.add(scissors);

        addComponent(this, buttonPanel, 1, gridy++, 3, 1, 
                rightInsets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);


        JLabel picture = new JLabel(
                createImageIcon("rockpaperscissors.png"));
        addComponent(this, picture, 0, gridy++, 4, 1, 
                insets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);

        cont = new JButton("Continue");
        cont.setFont(new Font("Arial", Font.PLAIN, 20));
        cont.addActionListener(this);
        cont.setActionCommand("continue");
        addComponent(this, cont, 0, gridy++, 4, 1, 
                insets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);

        JLabel YOURchoice = new JLabel("Your choice:");
        YOURchoice.setFont(new Font("Arial", Font.PLAIN, 20));
        addComponent(this, YOURchoice, 0, gridy, 1, 1, 
                insets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        YOURpic = new JLabel("--");
        addComponent(this, YOURpic, 1, gridy, 1, 1, 
                rightInsets, GridBagConstraints.LINE_END,
                GridBagConstraints.HORIZONTAL);

        JLabel COMPchoice = new JLabel("Computer's choice:");
        COMPchoice.setFont(new Font("Arial", Font.PLAIN, 20));
        addComponent(this, COMPchoice, 2, gridy, 1, 1, 
                rightInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        COMPpic = new JLabel("--");
        addComponent(this, COMPpic, 3, gridy++, 1, 1, 
                rightInsets, GridBagConstraints.LINE_END,
                GridBagConstraints.HORIZONTAL);

        results = new JLabel("--");
        results.setHorizontalAlignment(JLabel.CENTER);
        results.setFont(new Font("Arial", Font.BOLD, 40));
        addComponent(this, results, 0, gridy++, 4, 1, 
                insets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);


        JLabel YOURscore = new JLabel("Your score: ");
        YOURscore.setFont(new Font("Arial", Font.ITALIC, 35));
        addComponent(this, YOURscore, 0, gridy, 1, 1, 
                insets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);


        YOURscore2 = new JLabel("--");
        YOURscore2.setFont(new Font("Arial", Font.ITALIC, 35));
        addComponent(this, YOURscore2, 1, gridy, 1, 1, 
                rightInsets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);

        JLabel COMPscore = new JLabel("Computer's score: ");
        COMPscore.setFont(new Font("Arial", Font.ITALIC, 35));
        addComponent(this, COMPscore, 2, gridy, 1, 1, 
                rightInsets, GridBagConstraints.LINE_START,
                GridBagConstraints.HORIZONTAL);

        COMPscore2 = new JLabel("--");
        COMPscore2.setFont(new Font("Arial", Font.ITALIC, 35));
        addComponent(this, COMPscore2, 3, gridy++, 1, 1, 
                rightInsets, GridBagConstraints.CENTER,
                GridBagConstraints.HORIZONTAL);

    } // end constructor

    private void addComponent(Container container, 
            Component component, int gridx, int gridy, 
            int gridwidth, int gridheight, Insets insets, 
            int anchor, int fill) {
        GridBagConstraints gbc = new GridBagConstraints(
                gridx, gridy, gridwidth, gridheight, 
                1.0, 1.0, anchor, fill, insets, 0, 0);
        container.add(component, gbc);
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        int n = (int) (Math.random() * 3 + 1);

        if (e.getActionCommand().equals("continue")) {
            if (n == 1) {
                COMPpic.setIcon(rockIcon);
            } else if (n == 2) {
                COMPpic.setIcon(paperIcon);
            } else {
                COMPpic.setIcon(scissorsIcon);
            }
        }

        if (e.getActionCommand().equals("rock")) {
            YOURpic.setIcon(rockIcon);
            if (n == 1)
                results.setText("Tie");
            else if (n == 2) {
                results.setText("Computer wins");
                theirs++;
            } else if (n == 3) {
                results.setText("You win");
                yours++;
            }

        } else if (e.getActionCommand().equals("paper")) {
            YOURpic.setIcon(paperIcon);
            if (n == 1) {
                results.setText("You win");
                yours++;
            } else if (n == 2)
                results.setText("Tie");
            else if (n == 3) {
                results.setText("You lose");
                theirs++;
            }
        } else if (e.getActionCommand().equals("scissors")) {
            YOURpic.setIcon(scissorsIcon);
            if (n == 1) {
                results.setText("You lose");
                theirs++;
            } else if (n == 2) {
                results.setText("You win");
                yours++;
            } else if (n == 3)
                results.setText("Computer wins");
        }

        YOURscore2.setText(" " + yours);
        COMPscore2.setText(" " + theirs);
    }

    private ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = getClass().getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }
} // end main