当日总结

用java实现四则预算随机出题的界面化
import java.awt.;
import java.util.;
import javax.swing.*;
//import java.awt.List;
import java.util.List;
import javax.swing.Timer;
public class MathQuizWithTimer extends JFrame {
private Random random = new Random();
private int totalQuestions = 30;
private int correctCount = 0;

// 存储题目信息的列表
private List<Question> questions = new ArrayList<>();

// 计时相关
private Timer timer;
private long startTime;
private JLabel timeLabel;
private int secondsElapsed = 0;

// GUI组件
private JPanel questionsPanel;
private JScrollPane scrollPane;
private JButton submitButton;
private JLabel resultLabel;

public MathQuizWithTimer() {
    // 设置窗口基本属性
    setTitle("数学测验 - 计时版");
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    setSize(600, 600);
    setLocationRelativeTo(null); // 窗口居中

    // 初始化界面
    initUI();

    // 先初始化计时器（关键修正）
    initTimer();

    // 再生成题目（此时timer已被初始化）
    generateAllQuestions();

    // 显示所有题目
    displayAllQuestions();
}

private void initUI() {
    // 主面板使用边界布局
    JPanel mainPanel = new JPanel(new BorderLayout());
    mainPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));

    // 顶部：计时标签和标题
    JPanel topPanel = new JPanel(new BorderLayout());

    JLabel titleLabel = new JLabel("数学测验", SwingConstants.CENTER);
    titleLabel.setFont(new Font("宋体", Font.BOLD, 20));
    topPanel.add(titleLabel, BorderLayout.NORTH);

    // 计时标签
    timeLabel = new JLabel("用时: 00:00", SwingConstants.CENTER);
    timeLabel.setFont(new Font("宋体", Font.PLAIN, 16));
    timeLabel.setBorder(BorderFactory.createEmptyBorder(5, 0, 10, 0));
    topPanel.add(timeLabel, BorderLayout.SOUTH);

    mainPanel.add(topPanel, BorderLayout.NORTH);

    // 中间：题目区域
    questionsPanel = new JPanel();
    questionsPanel.setLayout(new GridLayout(0, 1, 5, 5)); // 垂直排列题目
    scrollPane = new JScrollPane(questionsPanel);
    scrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
    mainPanel.add(scrollPane, BorderLayout.CENTER);

    // 底部：提交按钮和结果
    JPanel bottomPanel = new JPanel(new BorderLayout());
    bottomPanel.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));

    submitButton = new JButton("提交答案");
    submitButton.setFont(new Font("宋体", Font.PLAIN, 16));
    submitButton.addActionListener(e -> checkAllAnswers());
    bottomPanel.add(submitButton, BorderLayout.NORTH);

    resultLabel = new JLabel("", SwingConstants.CENTER);
    resultLabel.setFont(new Font("宋体", Font.PLAIN, 16));
    bottomPanel.add(resultLabel, BorderLayout.SOUTH);

    mainPanel.add(bottomPanel, BorderLayout.SOUTH);

    // 添加主面板到窗口
    add(mainPanel);
}

// 初始化计时器
private void initTimer() {
    timer = new Timer(1000, e -> {
        secondsElapsed++;
        updateTimeDisplay();
    });
}

// 更新时间显示
private void updateTimeDisplay() {
    int minutes = secondsElapsed / 60;
    int seconds = secondsElapsed % 60;
    timeLabel.setText(String.format("用时: %02d:%02d", minutes, seconds));
}

// 生成所有题目
private void generateAllQuestions() {
    Set<String> usedQuestions = new HashSet<>();
    questions.clear();

    while (questions.size() < totalQuestions) {
        int num1 = random.nextInt(100) + 1;
        int num2 = random.nextInt(100) + 1;
        int op = random.nextInt(4) + 1;

        // 检查题目是否符合条件
        if (!judge(num1, num2, op)) {
            continue;
        }

        // 生成题目文本和正确答案
        String questionText = "";
        int correctAnswer = 0;

        switch (op) {
            case 1:
                correctAnswer = num1 + num2;
                questionText = num1 + "+" + num2 + "=";
                break;
            case 2:
                correctAnswer = num1 - num2;
                questionText = num1 + "-" + num2 + "=";
                break;
            case 3:
                correctAnswer = num1 * num2;
                questionText = num1 + "*" + num2 + "=";
                break;
            case 4:
                correctAnswer = num1 / num2;
                questionText = num1 + "/" + num2 + "=";
                break;
        }

        // 检查题目是否重复
        if (!usedQuestions.contains(questionText)) {
            usedQuestions.add(questionText);
            questions.add(new Question(questionText, correctAnswer));
        }
    }

    // 开始计时
    startTime = System.currentTimeMillis();
    timer.start();
}

// 显示所有题目
private void displayAllQuestions() {
    questionsPanel.removeAll();

    for (int i = 0; i < questions.size(); i++) {
        int questionNumber = i + 1;
        Question question = questions.get(i);

        // 每个题目使用一个面板显示
        JPanel questionPanel = new JPanel(new FlowLayout(FlowLayout.LEFT, 10, 5));

        // 题号标签
        JLabel numberLabel = new JLabel(questionNumber + ". ");
        numberLabel.setFont(new Font("宋体", Font.PLAIN, 14));

        // 题目文本
        JLabel textLabel = new JLabel(question.getQuestionText());
        textLabel.setFont(new Font("宋体", Font.PLAIN, 14));
        textLabel.setPreferredSize(new Dimension(150, 20));

        // 答案输入框
        JTextField answerField = new JTextField(5);
        answerField.setFont(new Font("宋体", Font.PLAIN, 14));
        answerField.setName(String.valueOf(i)); // 用索引作为名称，方便后续获取

        // 添加到题目面板
        questionPanel.add(numberLabel);
        questionPanel.add(textLabel);
        questionPanel.add(answerField);

        // 添加到总面板
        questionsPanel.add(questionPanel);
    }

    // 刷新界面
    questionsPanel.revalidate();
    questionsPanel.repaint();
}

// 检查所有答案
private void checkAllAnswers() {
    // 停止计时
    timer.stop();

    // 禁用提交按钮，防止重复提交
    submitButton.setEnabled(false);

    correctCount = 0;
    List<String> wrongQuestions = new ArrayList<>();

    // 遍历所有题目面板，获取答案
    Component[] components = questionsPanel.getComponents();
    for (Component component : components) {
        if (component instanceof JPanel) {
            JPanel questionPanel = (JPanel) component;
            JTextField answerField = null;
            JLabel textLabel = null;

            // 从面板中找到输入框和题目标签
            for (Component comp : questionPanel.getComponents()) {
                if (comp instanceof JTextField) {
                    answerField = (JTextField) comp;
                }
                // 修正：先判断是JLabel，转换后再调用getText()
                else if (comp instanceof JLabel) {
                    JLabel label = (JLabel) comp; // 强制转换为JLabel
                    if (!label.getText().endsWith(". ")) { // 现在可以安全调用getText()
                        textLabel = label;
                    }
                }
            }

            if (answerField != null && textLabel != null) {
                try {
                    // 获取题目索引
                    int index = Integer.parseInt(answerField.getName());
                    Question question = questions.get(index);

                    // 获取用户答案
                    String answerText = answerField.getText().trim();
                    if (answerText.isEmpty()) {
                        // 未答题视为错误
                        wrongQuestions.add((index + 1) + ". " + question.getQuestionText() + question.getCorrectAnswer());
                        answerField.setBackground(Color.PINK); // 错误答案标红
                        continue;
                    }

                    int userAnswer = Integer.parseInt(answerText);

                    // 检查答案
                    if (userAnswer == question.getCorrectAnswer()) {
                        correctCount++;
                        answerField.setBackground(Color.GREEN); // 正确答案标绿
                    } else {
                        wrongQuestions.add((index + 1) + ". " + question.getQuestionText() + question.getCorrectAnswer());
                        answerField.setBackground(Color.PINK); // 错误答案标红
                    }
                } catch (NumberFormatException e) {
                    // 非数字输入视为错误
                    int index = Integer.parseInt(answerField.getName());
                    Question question = questions.get(index);
                    wrongQuestions.add((index + 1) + ". " + question.getQuestionText() + question.getCorrectAnswer());
                    answerField.setBackground(Color.PINK);
                }

                // 禁用输入框
                answerField.setEnabled(false);
            }
        }
    }

    // 显示结果
    double rate = (double) correctCount / totalQuestions * 100;
    int wrongCount = totalQuestions - correctCount;

    String result = String.format(
            "答题完成！总用时: %02d:%02d，正确: %d 题，错误: %d 题，正确率: %.1f%%",
            secondsElapsed / 60, secondsElapsed % 60,
            correctCount, wrongCount, rate
    );
    resultLabel.setText(result);

    // 显示错题列表
    showWrongQuestionsDialog(wrongQuestions);
}

// 显示错题列表对话框
private void showWrongQuestionsDialog(List<String> wrongQuestions) {
    JTextArea textArea = new JTextArea(10, 30);
    textArea.setFont(new Font("宋体", Font.PLAIN, 14));
    textArea.setEditable(false);

    if (wrongQuestions.isEmpty()) {
        textArea.setText("恭喜，没有错题！");
    } else {
        textArea.append("错题列表：\n");
        for (String question : wrongQuestions) {
            textArea.append(question + "\n");
        }
    }

    JScrollPane scrollPane = new JScrollPane(textArea);
    JOptionPane.showMessageDialog(
            this, scrollPane, "测验结果", JOptionPane.INFORMATION_MESSAGE
    );
}

// 判断题目是否符合条件
public static boolean judge(int x, int y, int op) {
    switch (op) {
        case 2: // 减法，确保结果非负
            if (x < y) {
                return false;
            }
            break;
        case 3: // 乘法，确保结果不超过1000
            if (x * y >= 1000) {
                return false;
            }
            break;
        case 4: // 除法，确保能整除且除数不为0
            if (y == 0 || x % y != 0) {
                return false;
            }
            break;
    }
    return true;
}

// 题目类，存储题目文本和正确答案
private class Question {
    private String questionText;
    private int correctAnswer;

    public Question(String questionText, int correctAnswer) {
        this.questionText = questionText;
        this.correctAnswer = correctAnswer;
    }

    public String getQuestionText() {
        return questionText;
    }

    public int getCorrectAnswer() {
        return correctAnswer;
    }
}

public static void main(String[] args) {
    // 在事件调度线程中运行界面
    SwingUtilities.invokeLater(() -> {
        new MathQuizWithTimer().setVisible(true);
    });
}

}