math_question/view/ExamFrame.java

package view;
import controller.ExamController;
import model.Question;
import javax.swing.*;
import java.awt.*;
import java.util.List;

public class ExamFrame extends JFrame {
    private List<Question> questions;
    private int current = 0;
    private int[] answers;
    private ButtonGroup group;
    private JButton nextBtn;
    private JButton prevBtn;

    public ExamFrame(ExamController controller, List<Question> questions) {
        this.questions = questions;
        this.answers = new int[questions.size()];
        for (int i = 0; i < answers.length; i++) answers[i] = -1;

        setTitle("考试");
        setSize(500, 300);
        setLocationRelativeTo(null);

        JPanel panel = new JPanel(new BorderLayout());
        JLabel questionLabel = new JLabel();
        group = new ButtonGroup();
        JRadioButton[] options = new JRadioButton[4];
        JPanel optionsPanel = new JPanel(new GridLayout(4, 1));

        for (int i = 0; i < 4; i++) {
            options[i] = new JRadioButton();
            group.add(options[i]);
            optionsPanel.add(options[i]);
            int index = i;
            options[i].addActionListener(e -> answers[current] = index);
        }

        prevBtn = new JButton("上一题");
        nextBtn = new JButton("下一题");
        JButton submit = new JButton("提交");
        JPanel buttonPanel = new JPanel();

        prevBtn.addActionListener(e -> showQuestion(current - 1, questionLabel, options));
        nextBtn.addActionListener(e -> {
            if (current == questions.size() - 1) {
                // 已经是最后一题，提示用户
                JOptionPane.showMessageDialog(this,
                        "已经是最后一题！\n请点击提交按钮完成考试。",
                        "提示",
                        JOptionPane.INFORMATION_MESSAGE);
            } else {
                showQuestion(current + 1, questionLabel, options);
            }
        });

        submit.addActionListener(e -> {
            // 检查是否有未答题目
            int unanswered = 0;
            for (int answer : answers) {
                if (answer == -1) unanswered++;
            }

            String message;
            if (unanswered > 0) {
                message = "还有 " + unanswered + " 道题目未作答，确定要提交吗？";
            } else {
                message = "确定要提交试卷吗？";
            }

            // 确认提交对话框
            int result = JOptionPane.showConfirmDialog(
                    this,
                    message,
                    "确认提交",
                    JOptionPane.YES_NO_OPTION,
                    JOptionPane.QUESTION_MESSAGE
            );

            if (result == JOptionPane.YES_OPTION) {
                int score = 0;
                for (int i = 0; i < questions.size(); i++) {
                    if (answers[i] == questions.get(i).getCorrectAnswer()) score++;
                }
                controller.showResult(score, questions.size());
                dispose();
            }
        });

        buttonPanel.add(prevBtn);
        buttonPanel.add(nextBtn);
        buttonPanel.add(submit);

        panel.add(questionLabel, BorderLayout.NORTH);
        panel.add(optionsPanel, BorderLayout.CENTER);
        panel.add(buttonPanel, BorderLayout.SOUTH);

        add(panel);
        showQuestion(0, questionLabel, options);
        setVisible(true);
    }

    private void showQuestion(int index, JLabel label, JRadioButton[] options) {
        if (index < 0 || index >= questions.size()) return;
        current = index;
        Question q = questions.get(index);
        label.setText("第" + (index + 1) + "题: " + q.getContent() + " (" + (index + 1) + "/" + questions.size() + ")");

        List<String> optionTexts = q.getOptions().getOptions();

        // 先清空所有选项的选择状态
        group.clearSelection();

        // 设置选项文本，并根据当前题目的答案状态设置选择
        for (int i = 0; i < 4; i++) {
            options[i].setText(optionTexts.get(i));
            if (answers[current] == i) {
                options[i].setSelected(true);
            }
        }

        // 更新按钮状态
        updateButtonStates();
    }

    private void updateButtonStates() {
        // 上一题按钮状态
        prevBtn.setEnabled(current > 0);

        // 下一题按钮状态
        nextBtn.setEnabled(current < questions.size() - 1);

        // 如果是最后一题，修改下一题按钮文本为提示
        if (current == questions.size() - 1) {
            nextBtn.setText("最后一题");
        } else {
            nextBtn.setText("下一题");
        }
    }
}