doc/数学学习软件 - 用户界面与交互控制说明文档.md

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+# 带UI的小初高数学学习软件
+
+## 引言
+
+本项目旨在为小学、初中和高中学生提供一个数学学习平台，通过图形用户界面（GUI）与用户进行交互。系统包含用户注册、登录、答题等功能，旨在帮助学生通过练习题目提高数学水平。通过该项目，用户可以注册账号、登录、设置密码、接收验证码、选择题目数量并参与答题，最终获取成绩反馈。
+
+## 需求分析
+
+### 用户需求
+- **用户群体**：小学、初中和高中学生。
+- **主要功能**：
+    1. **用户注册**：用户提供邮箱地址，接收注册码并完成注册。
+    2. **用户登录**：通过注册的用户名和密码登录。
+    3. **答题功能**：用户根据所选学段生成题目并进行选择题答题。
+    4. **密码设置与修改**：设置密码需满足长度和字符要求，且用户可修改密码。
+    5. **邮箱验证码**：用户注册时，通过邮箱发送验证码进行身份验证。
+    6. **成绩评定**：完成答题后，系统自动计算得分并显示。
+
+### 系统功能
+- **图形界面**：包括欢迎页面、注册页面、登录页面、题目页面和成绩页面等。
+- **事件处理**：用户操作界面后触发相应的事件（如点击按钮提交、输入框验证）。
+- **邮件服务**：通过QQ邮箱服务发送验证码。
+- **界面布局**：界面设计需简洁、易于操作。
+
+## 系统设计
+
+### 系统设计架构
+
+本项目采用 **MVC**（Model-View-Controller）设计模式，分为 **模型层**（Model）、**视图层**（View）、和 **控制器层**（Controller）。这种架构使得应用程序更加模块化，易于维护和扩展。下面是对各个模块的详细分析和代码实现的具体说明。
+
+#### 1. **Model（模型层）**
+
+模型层负责处理程序的核心数据逻辑，进行业务逻辑的处理和数据的存储。在本项目中，模型层并不涉及数据库存储，所有数据都保存在内存中，程序退出时数据丢失。
+
+##### 主要类：
+
+##### b **User.java**（假设该类存在于项目中，负责用户信息管理）
+
+```java
+public class User {
+    private String username;
+    private String password;
+    private String email;
+    
+    public User(String username, String password, String email) {
+        this.username = username;
+        this.password = password;
+        this.email = email;
+    }
+
+    public String getUsername() {
+        return username;
+    }
+
+    public String getPassword() {
+        return password;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+}
+```
+#### 2. **View（视图层）**
+
+视图层负责用户界面的展示。它接收用户输入，并将其传递给控制器层；同时，接收控制器层传递的数据并更新用户界面。这里使用 Java Swing 库构建图形用户界面。
+
+#### 主要类：
+
+#### **MathLearningApp.java**（主应用程序）
+```java
+import javax.swing.*;
+
+public class MathLearningApp {
+public static void main(String[] args) {
+JFrame frame = new JFrame("Math Learning App");
+JButton registerButton = new JButton("Register");
+registerButton.addActionListener(e -> {
+// 弹出注册界面
+new RegistrationForm().setVisible(true);
+});
+frame.add(registerButton);
+frame.setSize(300, 200);
+frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+frame.setVisible(true);
+}
+}
+```
+**说明：**
+- **MathLearningApp.java** 类是应用程序的主入口，创建了一个 `JFrame` 作为主窗口，并添加了一个注册按钮。点击按钮时，会弹出 `RegistrationForm`（注册表单）界面。
+#### **RegistrationForm.java**（注册界面，假设代码存在）
+```java 
+public class RegistrationForm extends JFrame {
+public RegistrationForm() {
+setTitle("User Registration");
+setSize(300, 200);
+setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
+
+        JTextField emailField = new JTextField();
+        JPasswordField passwordField = new JPasswordField();
+        JButton submitButton = new JButton("Submit");
+        
+        submitButton.addActionListener(e -> {
+            String email = emailField.getText();
+            String password = new String(passwordField.getPassword());
+            // 注册处理逻辑
+        });
+        
+        // 设置布局、添加组件等...
+    }
+}
+```
+**说明：**
+- **RegistrationForm.java** 类用于显示用户注册界面，包含了邮箱和密码输入框，以及一个提交按钮，按钮点击后会触发注册逻辑。
+#### 3. **Controller（控制器层）**
+
+控制器层负责接收用户的输入并更新模型和视图。它是模型和视图之间的桥梁。
+
+#### 主要类：
+
+#### **MathLearningAppMethods.java**（界面方法扩展类）
+
+```java
+public class MathLearningAppMethods {
+    public static void handleRegistration(String email, String password) {
+        // 校验邮箱格式
+        if (!isValidEmail(email)) {
+            JOptionPane.showMessageDialog(null, "Invalid email address!");
+            return;
+        }
+        
+        // 用户注册逻辑
+        User newUser = new User(email, password, email);
+        // 这里通常会调用模型层存储用户信息，但由于不使用数据库，暂时保存在内存中
+        System.out.println("User registered: " + newUser.getUsername());
+        
+        // 发送注册成功邮件（通过邮件服务）
+        sendVerificationEmail(email);
+    }
+    
+    private static boolean isValidEmail(String email) {
+        // 邮箱格式验证逻辑
+        return email.contains("@");
+    }
+    
+    private static void sendVerificationEmail(String email) {
+        // 使用 RealEmailSender 发送邮件
+        new RealEmailSender().sendEmail(email, "Verification Code", "123456");
+    }
+}
+```
+**说明：**
+- **MathLearningAppMethods.java** 中的 `handleRegistration` 方法处理用户的注册逻辑。首先，它验证邮箱格式，如果正确则创建一个新的 `User` 实例，接着通过 `RealEmailSender` 类发送验证邮件。
+
+---
+
+#### 4. **邮件发送服务**
+
+邮件服务模块用于处理邮件发送，项目中使用了 QQ 邮箱服务来发送验证码。
+
+#### 主要类：
+#### **QQEmailService.java**（QQ邮箱服务）
+```java
+public class QQEmailService {
+    public void sendVerificationCode(String email, String code) {
+        // 使用 QQ 邮箱的 SMTP 服务发送邮件
+        System.out.println("Sending verification code " + code + " to " + email);
+    }
+}
+```
+#### 4. **邮件发送服务**
+
+邮件服务模块用于处理邮件发送，项目中使用了 QQ 邮箱服务来发送验证码。
+
+#### 主要类：
+
+#### **QQEmailService.java**（QQ邮箱服务）
+
+**说明：**
+- **QQEmailService.java** 类负责通过 QQ 邮箱发送验证码。该服务并没有连接真实的 SMTP 服务器，实际操作中可以进一步配置邮箱服务器来实现邮件的发送。
+
+#### **RealEmailSender.java**（邮件发送器）
+
+```java
+public class RealEmailSender {
+    private QQEmailService emailService = new QQEmailService();
+
+    public void sendEmail(String recipient, String subject, String body) {
+        // 通过 QQEmailService 实现邮件的发送
+        emailService.sendVerificationCode(recipient, body);
+    }
+}
+```
+**说明：**
+- **RealEmailSender.java** 类负责邮件的实际发送操作，它调用了 `QQEmailService` 类来发送邮件。未来可以根据需要扩展更多邮件服务支持。
+
+### 总结
+
+- **Model（模型层）**：管理核心数据，处理用户信息和业务逻辑。
+- **View（视图层）**：构建图形用户界面，展示数据并与用户交互。
+- **Controller（控制器层）**：处理用户输入，协调模型和视图的交互。
+
+这种设计模式使得代码的结构更加清晰，易于维护。用户界面部分（视图）与业务逻辑部分（模型）相互独立，便于将来扩展更多功能，优化代码结构。### 数据设计
+本系统不使用数据库存储数据，所有用户数据（如注册信息、成绩等）都存储在内存中，程序运行期间临时保存。
+
+## 实现与运行
+
+### 环境与依赖
+- **开发语言**：Java 确保已安装Java环境（JDK 8及以上）
+- **GUI框架**：Java Swing
+- **邮件服务**：QQ邮箱SMTP服务
+- **运行平台**：支持Windows、macOS和Linux平台
+### 运行项目
+
+1. 编译并运行 `MathLearningApp.java` 文件，即可启动应用。
+2. 根据界面提示完成注册、登录和答题操作。
+
+### 功能实现
+
+#### 用户注册与登录：
+- 用户提供邮箱注册，接收并输入验证码完成注册。
+- 密码必须包含大小写字母和数字，且长度为6-10位。
+
+#### 答题流程：
+- 根据选择的年级生成题目，用户逐一作答。
+- 答题后自动计算成绩，并提供继续答题或退出的选项。
+
+#### 邮件验证：
+- 注册时通过 `QQEmailService.java` 发送验证码到用户邮箱。
+
+#### 界面管理：
+- 通过 `MathLearningAppMethods.java` 进行界面布局和用户交互。
+

src/MathLearningApp.java

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+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import java.util.*;
+import java.util.List;
+import java.util.regex.Pattern;
+// 邮件功能暂时使用模拟实现，不需要真实的邮件库
+import java.io.*;
+import java.nio.file.*;
+
+/**
+ * 带UI的小初高数学学习软件 - 主程序
+ * 基于原有命令行版本改写的GUI版本
+ */
+public class MathLearningApp extends JFrame {
+    private CardLayout cardLayout;
+    private JPanel mainPanel;
+    
+    // 用户管理
+    private Map<String, RegisteredUser> registeredUsers;
+    private RegisteredUser currentUser;
+    
+    // 题目管理
+    private MathQuestionGenerator questionGenerator;
+    private List<MultipleChoiceQuestion> currentQuestions;
+    private int currentQuestionIndex;
+    private int correctAnswers;
+    private String currentDifficulty;
+    
+    // 界面组件
+    private JTextField emailField;
+    private JTextField verificationCodeField;
+    private JPasswordField passwordField;
+    private JPasswordField confirmPasswordField;
+    private JPasswordField oldPasswordField;
+    private JLabel questionLabel;
+    private ButtonGroup answerGroup;
+    private JRadioButton[] answerButtons;
+    private JLabel scoreLabel;
+    
+    public MathLearningApp() {
+        initializeData();
+        initializeGUI();
+        loadUserData();
+    }
+    
+    /**
+     * 初始化数据
+     */
+    private void initializeData() {
+        registeredUsers = new HashMap<>();
+        questionGenerator = new MathQuestionGenerator();
+        currentQuestions = new ArrayList<>();
+        currentQuestionIndex = 0;
+        correctAnswers = 0;
+        answerButtons = new JRadioButton[4];
+    }
+    
+    /**
+     * 初始化GUI界面
+     */
+    private void initializeGUI() {
+        setTitle("小初高数学学习软件");
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setSize(800, 600);
+        setLocationRelativeTo(null);
+        
+        cardLayout = new CardLayout();
+        mainPanel = new JPanel(cardLayout);
+        
+        // 创建各个界面
+        createWelcomePanel();
+        createRegisterPanel();
+        createLoginPanel();
+        createPasswordSetupPanel();
+        createDifficultySelectionPanel();
+        createQuestionPanel();
+        createScorePanel();
+        createPasswordChangePanel();
+        
+        add(mainPanel);
+        
+        // 显示欢迎界面
+        cardLayout.show(mainPanel, "WELCOME");
+    }
+    
+    /**
+     * 创建欢迎界面
+     */
+    private void createWelcomePanel() {
+        JPanel panel = new JPanel(new BorderLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变背景
+                GradientPaint gradient = new GradientPaint(0, 0, new Color(135, 206, 250), 
+                                                         0, getHeight(), new Color(240, 248, 255));
+                g2.setPaint(gradient);
+                g2.fillRect(0, 0, getWidth(), getHeight());
+                
+                g2.dispose();
+            }
+        };
+        
+        // 标题面板
+        JPanel titlePanel = new JPanel();
+        titlePanel.setOpaque(false);
+        titlePanel.setBorder(BorderFactory.createEmptyBorder(80, 0, 50, 0));
+        
+        JLabel titleLabel = new JLabel("小初高数学学习软件", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 36));
+        titleLabel.setForeground(new Color(25, 25, 112));
+        
+        JLabel subtitleLabel = new JLabel("让数学学习变得更有趣", JLabel.CENTER);
+        subtitleLabel.setFont(new Font("微软雅黑", Font.PLAIN, 16));
+        subtitleLabel.setForeground(new Color(70, 130, 180));
+        subtitleLabel.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));
+        
+        titlePanel.setLayout(new BoxLayout(titlePanel, BoxLayout.Y_AXIS));
+        titlePanel.add(titleLabel);
+        titlePanel.add(subtitleLabel);
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel();
+        buttonPanel.setOpaque(false);
+        buttonPanel.setLayout(new FlowLayout(FlowLayout.CENTER, 30, 20));
+        
+        JButton registerButton = createStyledButton("用户注册", new Color(60, 179, 113));
+        JButton loginButton = createStyledButton("用户登录", new Color(70, 130, 180));
+        
+        registerButton.addActionListener(e -> cardLayout.show(mainPanel, "REGISTER"));
+        loginButton.addActionListener(e -> cardLayout.show(mainPanel, "LOGIN"));
+        
+        buttonPanel.add(registerButton);
+        buttonPanel.add(loginButton);
+        
+        // 底部信息
+        JLabel footerLabel = new JLabel("© 2025 数学学习软件 - 专业的数学学习平台", JLabel.CENTER);
+        footerLabel.setFont(new Font("微软雅黑", Font.PLAIN, 12));
+        footerLabel.setForeground(new Color(100, 100, 100));
+        footerLabel.setBorder(BorderFactory.createEmptyBorder(0, 0, 30, 0));
+        
+        panel.add(titlePanel, BorderLayout.NORTH);
+        panel.add(buttonPanel, BorderLayout.CENTER);
+        panel.add(footerLabel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "WELCOME");
+    }
+    
+    /**
+     * 创建注册界面
+     */
+    private void createRegisterPanel() {
+        JPanel panel = new JPanel(new BorderLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变背景
+                GradientPaint gradient = new GradientPaint(0, 0, new Color(250, 250, 250), 
+                                                         0, getHeight(), new Color(240, 248, 255));
+                g2.setPaint(gradient);
+                g2.fillRect(0, 0, getWidth(), getHeight());
+                
+                g2.dispose();
+            }
+        };
+        
+        // 标题面板
+        JPanel titlePanel = new JPanel();
+        titlePanel.setOpaque(false);
+        titlePanel.setBorder(BorderFactory.createEmptyBorder(40, 0, 30, 0));
+        
+        JLabel titleLabel = new JLabel("用户注册", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 28));
+        titleLabel.setForeground(new Color(25, 25, 112));
+        
+        JLabel subtitleLabel = new JLabel("请填写您的邮箱信息完成注册", JLabel.CENTER);
+        subtitleLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        subtitleLabel.setForeground(new Color(100, 100, 100));
+        subtitleLabel.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));
+        
+        titlePanel.setLayout(new BoxLayout(titlePanel, BoxLayout.Y_AXIS));
+        titlePanel.add(titleLabel);
+        titlePanel.add(subtitleLabel);
+        
+        // 表单面板 - 添加卡片样式
+        JPanel formContainer = new JPanel();
+        formContainer.setOpaque(false);
+        formContainer.setBorder(BorderFactory.createEmptyBorder(20, 50, 20, 50));
+        
+        JPanel formPanel = new JPanel(new GridBagLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 卡片阴影
+                g2.setColor(new Color(0, 0, 0, 20));
+                g2.fillRoundRect(5, 5, getWidth()-5, getHeight()-5, 20, 20);
+                
+                // 卡片背景
+                g2.setColor(Color.WHITE);
+                g2.fillRoundRect(0, 0, getWidth()-5, getHeight()-5, 20, 20);
+                
+                g2.dispose();
+            }
+        };
+        formPanel.setBorder(BorderFactory.createEmptyBorder(30, 40, 30, 40));
+        
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(15, 10, 15, 10);
+        
+        // 邮箱输入
+        gbc.gridx = 0; gbc.gridy = 0; gbc.anchor = GridBagConstraints.EAST;
+        JLabel emailLabel = new JLabel("邮箱地址:");
+        emailLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        emailLabel.setForeground(new Color(70, 70, 70));
+        formPanel.add(emailLabel, gbc);
+        
+        gbc.gridx = 1; gbc.anchor = GridBagConstraints.WEST;
+        emailField = new JTextField(20);
+        emailField.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        emailField.setBorder(BorderFactory.createCompoundBorder(
+            BorderFactory.createLineBorder(new Color(200, 200, 200), 1),
+            BorderFactory.createEmptyBorder(8, 12, 8, 12)
+        ));
+        formPanel.add(emailField, gbc);
+        
+        // 发送验证码按钮
+        gbc.gridx = 2;
+        JButton sendCodeButton = createStyledButton("发送验证码", new Color(255, 140, 0));
+        sendCodeButton.addActionListener(this::sendVerificationCode);
+        formPanel.add(sendCodeButton, gbc);
+        
+        // 验证码输入
+        gbc.gridx = 0; gbc.gridy = 1; gbc.gridwidth = 1; gbc.anchor = GridBagConstraints.EAST;
+        JLabel codeLabel = new JLabel("验证码:");
+        codeLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        codeLabel.setForeground(new Color(70, 70, 70));
+        formPanel.add(codeLabel, gbc);
+        
+        gbc.gridx = 1; gbc.anchor = GridBagConstraints.WEST;
+        verificationCodeField = new JTextField(20);
+        verificationCodeField.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        verificationCodeField.setBorder(BorderFactory.createCompoundBorder(
+            BorderFactory.createLineBorder(new Color(200, 200, 200), 1),
+            BorderFactory.createEmptyBorder(8, 12, 8, 12)
+        ));
+        formPanel.add(verificationCodeField, gbc);
+        
+        formContainer.add(formPanel);
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 20, 30));
+        buttonPanel.setOpaque(false);
+        
+        JButton registerButton = createStyledButton("注册", new Color(60, 179, 113));
+        JButton backButton = createStyledButton("返回", new Color(128, 128, 128));
+        
+        registerButton.addActionListener(this::handleRegister);
+        backButton.addActionListener(e -> cardLayout.show(mainPanel, "WELCOME"));
+        
+        buttonPanel.add(registerButton);
+        buttonPanel.add(backButton);
+        
+        panel.add(titlePanel, BorderLayout.NORTH);
+        panel.add(formContainer, BorderLayout.CENTER);
+        panel.add(buttonPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "REGISTER");
+    }
+    
+    /**
+     * 创建登录界面
+     */
+    private void createLoginPanel() {
+        JPanel panel = new JPanel(new BorderLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变背景
+                GradientPaint gradient = new GradientPaint(0, 0, new Color(250, 250, 250), 
+                                                         0, getHeight(), new Color(240, 248, 255));
+                g2.setPaint(gradient);
+                g2.fillRect(0, 0, getWidth(), getHeight());
+                
+                g2.dispose();
+            }
+        };
+        
+        // 标题面板
+        JPanel titlePanel = new JPanel();
+        titlePanel.setOpaque(false);
+        titlePanel.setBorder(BorderFactory.createEmptyBorder(60, 0, 40, 0));
+        
+        JLabel titleLabel = new JLabel("用户登录", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 28));
+        titleLabel.setForeground(new Color(25, 25, 112));
+        
+        JLabel subtitleLabel = new JLabel("请输入您的账户信息", JLabel.CENTER);
+        subtitleLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        subtitleLabel.setForeground(new Color(100, 100, 100));
+        subtitleLabel.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));
+        
+        titlePanel.setLayout(new BoxLayout(titlePanel, BoxLayout.Y_AXIS));
+        titlePanel.add(titleLabel);
+        titlePanel.add(subtitleLabel);
+        
+        // 表单面板 - 添加卡片样式
+        JPanel formContainer = new JPanel();
+        formContainer.setOpaque(false);
+        formContainer.setBorder(BorderFactory.createEmptyBorder(20, 80, 20, 80));
+        
+        JPanel formPanel = new JPanel(new GridBagLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 卡片阴影
+                g2.setColor(new Color(0, 0, 0, 20));
+                g2.fillRoundRect(5, 5, getWidth()-5, getHeight()-5, 20, 20);
+                
+                // 卡片背景
+                g2.setColor(Color.WHITE);
+                g2.fillRoundRect(0, 0, getWidth()-5, getHeight()-5, 20, 20);
+                
+                g2.dispose();
+            }
+        };
+        formPanel.setBorder(BorderFactory.createEmptyBorder(40, 50, 40, 50));
+        
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(20, 10, 20, 10);
+        
+        // 用户名(邮箱)输入
+        gbc.gridx = 0; gbc.gridy = 0; gbc.anchor = GridBagConstraints.EAST;
+        JLabel emailLabel = new JLabel("用户名(邮箱):");
+        emailLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        emailLabel.setForeground(new Color(70, 70, 70));
+        formPanel.add(emailLabel, gbc);
+        
+        gbc.gridx = 1; gbc.anchor = GridBagConstraints.WEST;
+        JTextField loginEmailField = new JTextField(25);
+        loginEmailField.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        loginEmailField.setBorder(BorderFactory.createCompoundBorder(
+            BorderFactory.createLineBorder(new Color(200, 200, 200), 1),
+            BorderFactory.createEmptyBorder(10, 15, 10, 15)
+        ));
+        formPanel.add(loginEmailField, gbc);
+        
+        // 密码输入
+        gbc.gridx = 0; gbc.gridy = 1; gbc.anchor = GridBagConstraints.EAST;
+        JLabel passwordLabel = new JLabel("密码:");
+        passwordLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        passwordLabel.setForeground(new Color(70, 70, 70));
+        formPanel.add(passwordLabel, gbc);
+        
+        gbc.gridx = 1; gbc.anchor = GridBagConstraints.WEST;
+        JPasswordField loginPasswordField = new JPasswordField(25);
+        loginPasswordField.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        loginPasswordField.setBorder(BorderFactory.createCompoundBorder(
+            BorderFactory.createLineBorder(new Color(200, 200, 200), 1),
+            BorderFactory.createEmptyBorder(10, 15, 10, 15)
+        ));
+        formPanel.add(loginPasswordField, gbc);
+        
+        formContainer.add(formPanel);
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 20, 40));
+        buttonPanel.setOpaque(false);
+        
+        JButton loginButton = createStyledButton("登录", new Color(70, 130, 180));
+        JButton backButton = createStyledButton("返回", new Color(128, 128, 128));
+        
+        loginButton.addActionListener(e -> handleLogin(loginEmailField.getText(), 
+                                                      new String(loginPasswordField.getPassword())));
+        backButton.addActionListener(e -> cardLayout.show(mainPanel, "WELCOME"));
+        
+        buttonPanel.add(loginButton);
+        buttonPanel.add(backButton);
+        
+        panel.add(titlePanel, BorderLayout.NORTH);
+        panel.add(formContainer, BorderLayout.CENTER);
+        panel.add(buttonPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "LOGIN");
+    }
+    
+    /**
+     * 创建密码设置界面
+     */
+    private void createPasswordSetupPanel() {
+        JPanel panel = new JPanel(new BorderLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变背景
+                GradientPaint gradient = new GradientPaint(0, 0, new Color(250, 250, 250), 
+                                                         0, getHeight(), new Color(240, 248, 255));
+                g2.setPaint(gradient);
+                g2.fillRect(0, 0, getWidth(), getHeight());
+                
+                g2.dispose();
+            }
+        };
+        
+        // 标题面板
+        JPanel titlePanel = new JPanel();
+        titlePanel.setOpaque(false);
+        titlePanel.setBorder(BorderFactory.createEmptyBorder(50, 0, 30, 0));
+        
+        JLabel titleLabel = new JLabel("设置密码", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 28));
+        titleLabel.setForeground(new Color(25, 25, 112));
+        
+        JLabel subtitleLabel = new JLabel("请为您的账户设置安全密码", JLabel.CENTER);
+        subtitleLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        subtitleLabel.setForeground(new Color(100, 100, 100));
+        subtitleLabel.setBorder(BorderFactory.createEmptyBorder(10, 0, 0, 0));
+        
+        // 提示信息
+        JLabel hintLabel = new JLabel("<html><center>密码要求：6-10位，必须包含大小写字母和数字</center></html>", JLabel.CENTER);
+        hintLabel.setFont(new Font("微软雅黑", Font.PLAIN, 12));
+        hintLabel.setForeground(new Color(150, 150, 150));
+        hintLabel.setBorder(BorderFactory.createEmptyBorder(15, 0, 0, 0));
+        
+        titlePanel.setLayout(new BoxLayout(titlePanel, BoxLayout.Y_AXIS));
+        titlePanel.add(titleLabel);
+        titlePanel.add(subtitleLabel);
+        titlePanel.add(hintLabel);
+        
+        // 表单面板 - 添加卡片样式
+        JPanel formContainer = new JPanel();
+        formContainer.setOpaque(false);
+        formContainer.setBorder(BorderFactory.createEmptyBorder(30, 80, 30, 80));
+        
+        JPanel formPanel = new JPanel(new GridBagLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 卡片阴影
+                g2.setColor(new Color(0, 0, 0, 20));
+                g2.fillRoundRect(5, 5, getWidth()-5, getHeight()-5, 20, 20);
+                
+                // 卡片背景
+                g2.setColor(Color.WHITE);
+                g2.fillRoundRect(0, 0, getWidth()-5, getHeight()-5, 20, 20);
+                
+                g2.dispose();
+            }
+        };
+        formPanel.setBorder(BorderFactory.createEmptyBorder(40, 50, 40, 50));
+        
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(20, 10, 20, 10);
+        
+        // 密码输入
+        gbc.gridx = 0; gbc.gridy = 0; gbc.anchor = GridBagConstraints.EAST;
+        JLabel passwordLabel = new JLabel("输入密码:");
+        passwordLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        passwordLabel.setForeground(new Color(70, 70, 70));
+        formPanel.add(passwordLabel, gbc);
+        
+        gbc.gridx = 1; gbc.anchor = GridBagConstraints.WEST;
+        passwordField = new JPasswordField(25);
+        passwordField.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        passwordField.setBorder(BorderFactory.createCompoundBorder(
+            BorderFactory.createLineBorder(new Color(200, 200, 200), 1),
+            BorderFactory.createEmptyBorder(10, 15, 10, 15)
+        ));
+        formPanel.add(passwordField, gbc);
+        
+        // 确认密码
+        gbc.gridx = 0; gbc.gridy = 1; gbc.anchor = GridBagConstraints.EAST;
+        JLabel confirmLabel = new JLabel("确认密码:");
+        confirmLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        confirmLabel.setForeground(new Color(70, 70, 70));
+        formPanel.add(confirmLabel, gbc);
+        
+        gbc.gridx = 1; gbc.anchor = GridBagConstraints.WEST;
+        confirmPasswordField = new JPasswordField(25);
+        confirmPasswordField.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        confirmPasswordField.setBorder(BorderFactory.createCompoundBorder(
+            BorderFactory.createLineBorder(new Color(200, 200, 200), 1),
+            BorderFactory.createEmptyBorder(10, 15, 10, 15)
+        ));
+        formPanel.add(confirmPasswordField, gbc);
+        
+        formContainer.add(formPanel);
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 0, 40));
+        buttonPanel.setOpaque(false);
+        
+        JButton setPasswordButton = createStyledButton("设置密码", new Color(60, 179, 113));
+        setPasswordButton.addActionListener(this::handlePasswordSetup);
+        buttonPanel.add(setPasswordButton);
+        
+        panel.add(titlePanel, BorderLayout.NORTH);
+        panel.add(formContainer, BorderLayout.CENTER);
+        panel.add(buttonPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "PASSWORD_SETUP");
+    }
+    
+    /**
+     * 创建难度选择界面
+     */
+    private void createDifficultySelectionPanel() {
+        JPanel panel = new JPanel(new BorderLayout()) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变背景
+                GradientPaint gradient = new GradientPaint(0, 0, new Color(240, 248, 255), 
+                                                         0, getHeight(), new Color(230, 240, 250));
+                g2.setPaint(gradient);
+                g2.fillRect(0, 0, getWidth(), getHeight());
+                
+                g2.dispose();
+            }
+        };
+        
+        // 标题面板
+        JPanel titlePanel = new JPanel();
+        titlePanel.setOpaque(false);
+        titlePanel.setBorder(BorderFactory.createEmptyBorder(60, 0, 40, 0));
+        
+        JLabel titleLabel = new JLabel("选择学习难度", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 32));
+        titleLabel.setForeground(new Color(25, 25, 112));
+        
+        JLabel subtitleLabel = new JLabel("选择适合您的数学学习级别", JLabel.CENTER);
+        subtitleLabel.setFont(new Font("微软雅黑", Font.PLAIN, 16));
+        subtitleLabel.setForeground(new Color(70, 130, 180));
+        subtitleLabel.setBorder(BorderFactory.createEmptyBorder(15, 0, 0, 0));
+        
+        titlePanel.setLayout(new BoxLayout(titlePanel, BoxLayout.Y_AXIS));
+        titlePanel.add(titleLabel);
+        titlePanel.add(subtitleLabel);
+        
+        // 按钮面板
+        JPanel buttonContainer = new JPanel();
+        buttonContainer.setOpaque(false);
+        buttonContainer.setBorder(BorderFactory.createEmptyBorder(20, 80, 40, 80));
+        
+        JPanel buttonPanel = new JPanel(new GridLayout(3, 1, 0, 25));
+        buttonPanel.setOpaque(false);
+        
+        JButton elementaryButton = createLargeDifficultyButton("小学数学", new Color(255, 182, 193));
+        JButton middleButton = createLargeDifficultyButton("初中数学", new Color(173, 216, 230));
+        JButton highButton = createLargeDifficultyButton("高中数学", new Color(221, 160, 221));
+        
+        elementaryButton.addActionListener(e -> selectDifficulty("小学"));
+        middleButton.addActionListener(e -> selectDifficulty("初中"));
+        highButton.addActionListener(e -> selectDifficulty("高中"));
+        
+        buttonPanel.add(elementaryButton);
+        buttonPanel.add(middleButton);
+        buttonPanel.add(highButton);
+        
+        buttonContainer.add(buttonPanel);
+        
+        // 底部面板
+        JPanel bottomPanel = new JPanel(new FlowLayout(FlowLayout.CENTER, 30, 30));
+        bottomPanel.setOpaque(false);
+        
+        JButton changePasswordButton = createStyledButton("修改密码", new Color(255, 140, 0));
+        JButton logoutButton = createStyledButton("退出登录", new Color(220, 20, 60));
+        
+        changePasswordButton.addActionListener(e -> cardLayout.show(mainPanel, "PASSWORD_CHANGE"));
+        logoutButton.addActionListener(e -> {
+            currentUser = null;
+            cardLayout.show(mainPanel, "WELCOME");
+        });
+        
+        bottomPanel.add(changePasswordButton);
+        bottomPanel.add(logoutButton);
+        
+        panel.add(titlePanel, BorderLayout.NORTH);
+        panel.add(buttonContainer, BorderLayout.CENTER);
+        panel.add(bottomPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "DIFFICULTY_SELECTION");
+    }
+    
+    /**
+     * 创建答题界面
+     */
+    private void createQuestionPanel() {
+        JPanel panel = new JPanel(new BorderLayout());
+        panel.setBackground(Color.WHITE);
+        
+        // 顶部信息面板
+        JPanel topPanel = new JPanel(new BorderLayout());
+        topPanel.setBackground(Color.WHITE);
+        topPanel.setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20));
+        
+        JLabel progressLabel = new JLabel("", JLabel.LEFT);
+        progressLabel.setFont(new Font("微软雅黑", Font.PLAIN, 14));
+        
+        JLabel difficultyLabel = new JLabel("", JLabel.RIGHT);
+        difficultyLabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        
+        topPanel.add(progressLabel, BorderLayout.WEST);
+        topPanel.add(difficultyLabel, BorderLayout.EAST);
+        
+        // 题目面板
+        JPanel questionPanel = new JPanel(new BorderLayout());
+        questionPanel.setBackground(Color.WHITE);
+        questionPanel.setBorder(BorderFactory.createEmptyBorder(20, 40, 20, 40));
+        
+        questionLabel = new JLabel("", JLabel.CENTER);
+        questionLabel.setFont(new Font("微软雅黑", Font.PLAIN, 18));
+        questionLabel.setBorder(BorderFactory.createEmptyBorder(20, 0, 30, 0));
+        
+        // 选项面板
+        JPanel optionsPanel = new JPanel(new GridLayout(4, 1, 0, 15));
+        optionsPanel.setBackground(Color.WHITE);
+        
+        answerGroup = new ButtonGroup();
+        for (int i = 0; i < 4; i++) {
+            answerButtons[i] = new JRadioButton();
+            answerButtons[i].setFont(new Font("微软雅黑", Font.PLAIN, 16));
+            answerButtons[i].setBackground(Color.WHITE);
+            answerGroup.add(answerButtons[i]);
+            optionsPanel.add(answerButtons[i]);
+        }
+        
+        questionPanel.add(questionLabel, BorderLayout.NORTH);
+        questionPanel.add(optionsPanel, BorderLayout.CENTER);
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout());
+        buttonPanel.setBackground(Color.WHITE);
+        
+        JButton submitButton = createStyledButton("提交答案", new Color(70, 130, 180));
+        submitButton.addActionListener(this::handleAnswerSubmit);
+        buttonPanel.add(submitButton);
+        
+        panel.add(topPanel, BorderLayout.NORTH);
+        panel.add(questionPanel, BorderLayout.CENTER);
+        panel.add(buttonPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "QUESTION");
+    }
+    
+    /**
+     * 创建评分界面
+     */
+    private void createScorePanel() {
+        JPanel panel = new JPanel(new BorderLayout());
+        panel.setBackground(new Color(240, 248, 255));
+        
+        // 标题
+        JLabel titleLabel = new JLabel("答题结果", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 24));
+        titleLabel.setBorder(BorderFactory.createEmptyBorder(50, 0, 30, 0));
+        
+        // 分数显示
+        scoreLabel = new JLabel("", JLabel.CENTER);
+        scoreLabel.setFont(new Font("微软雅黑", Font.BOLD, 36));
+        scoreLabel.setForeground(new Color(70, 130, 180));
+        scoreLabel.setBorder(BorderFactory.createEmptyBorder(30, 0, 50, 0));
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout());
+        buttonPanel.setBackground(new Color(240, 248, 255));
+        
+        JButton continueButton = createStyledButton("继续做题", new Color(60, 179, 113));
+        JButton exitButton = createStyledButton("退出", new Color(220, 20, 60));
+        
+        continueButton.addActionListener(e -> cardLayout.show(mainPanel, "DIFFICULTY_SELECTION"));
+        exitButton.addActionListener(e -> {
+            currentUser = null;
+            cardLayout.show(mainPanel, "WELCOME");
+        });
+        
+        buttonPanel.add(continueButton);
+        buttonPanel.add(exitButton);
+        
+        panel.add(titleLabel, BorderLayout.NORTH);
+        panel.add(scoreLabel, BorderLayout.CENTER);
+        panel.add(buttonPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "SCORE");
+    }
+    
+    /**
+     * 创建密码修改界面
+     */
+    private void createPasswordChangePanel() {
+        JPanel panel = new JPanel(new BorderLayout());
+        panel.setBackground(Color.WHITE);
+        
+        // 标题
+        JLabel titleLabel = new JLabel("修改密码", JLabel.CENTER);
+        titleLabel.setFont(new Font("微软雅黑", Font.BOLD, 24));
+        titleLabel.setBorder(BorderFactory.createEmptyBorder(30, 0, 30, 0));
+        
+        // 表单面板
+        JPanel formPanel = new JPanel(new GridBagLayout());
+        formPanel.setBackground(Color.WHITE);
+        GridBagConstraints gbc = new GridBagConstraints();
+        gbc.insets = new Insets(10, 10, 10, 10);
+        
+        // 原密码
+        gbc.gridx = 0; gbc.gridy = 0;
+        formPanel.add(new JLabel("原密码:"), gbc);
+        gbc.gridx = 1;
+        oldPasswordField = new JPasswordField(20);
+        formPanel.add(oldPasswordField, gbc);
+        
+        // 新密码
+        gbc.gridx = 0; gbc.gridy = 1;
+        formPanel.add(new JLabel("新密码:"), gbc);
+        gbc.gridx = 1;
+        JPasswordField newPasswordField = new JPasswordField(20);
+        formPanel.add(newPasswordField, gbc);
+        
+        // 确认新密码
+        gbc.gridx = 0; gbc.gridy = 2;
+        formPanel.add(new JLabel("确认新密码:"), gbc);
+        gbc.gridx = 1;
+        JPasswordField confirmNewPasswordField = new JPasswordField(20);
+        formPanel.add(confirmNewPasswordField, gbc);
+        
+        // 按钮面板
+        JPanel buttonPanel = new JPanel(new FlowLayout());
+        buttonPanel.setBackground(Color.WHITE);
+        
+        JButton changeButton = createStyledButton("修改密码", new Color(60, 179, 113));
+        JButton backButton = createStyledButton("返回", new Color(128, 128, 128));
+        
+        changeButton.addActionListener(e -> handlePasswordChange(
+            new String(oldPasswordField.getPassword()),
+            new String(newPasswordField.getPassword()),
+            new String(confirmNewPasswordField.getPassword())
+        ));
+        backButton.addActionListener(e -> cardLayout.show(mainPanel, "DIFFICULTY_SELECTION"));
+        
+        buttonPanel.add(changeButton);
+        buttonPanel.add(backButton);
+        
+        panel.add(titleLabel, BorderLayout.NORTH);
+        panel.add(formPanel, BorderLayout.CENTER);
+        panel.add(buttonPanel, BorderLayout.SOUTH);
+        
+        mainPanel.add(panel, "PASSWORD_CHANGE");
+    }
+    
+    /**
+     * 创建样式化按钮
+     */
+    private JButton createStyledButton(String text, Color backgroundColor) {
+        return MathLearningAppMethods.createStyledButton(text, backgroundColor);
+    }
+    
+    /**
+     * 创建大型难度选择按钮
+     */
+    private JButton createLargeDifficultyButton(String text, Color backgroundColor) {
+        return MathLearningAppMethods.createLargeDifficultyButton(text, backgroundColor);
+    }
+    
+    /**
+     * 发送验证码
+     */
+    private void sendVerificationCode(ActionEvent e) {
+        MathLearningAppMethods.sendVerificationCode(e, emailField, registeredUsers);
+    }
+    
+    /**
+     * 处理用户注册
+     */
+    private void handleRegister(ActionEvent e) {
+        if (MathLearningAppMethods.handleRegister(emailField, verificationCodeField, 
+                                                 registeredUsers, cardLayout, mainPanel)) {
+            // 清空输入框
+            emailField.setText("");
+            verificationCodeField.setText("");
+        }
+    }
+    
+    /**
+     * 处理密码设置
+     */
+    private void handlePasswordSetup(ActionEvent e) {
+        if (MathLearningAppMethods.handlePasswordSetup(passwordField, confirmPasswordField,
+                                                      registeredUsers, cardLayout, mainPanel)) {
+            // 设置当前用户
+            for (RegisteredUser user : registeredUsers.values()) {
+                if (user.isVerified() && user.getPassword() != null) {
+                    currentUser = user;
+                    break;
+                }
+            }
+            // 清空密码框
+            passwordField.setText("");
+            confirmPasswordField.setText("");
+        }
+    }
+    
+    /**
+     * 处理用户登录
+     */
+    private void handleLogin(String email, String password) {
+        RegisteredUser user = MathLearningAppMethods.handleLogin(email, password, 
+                                                               registeredUsers, cardLayout, mainPanel);
+        if (user != null) {
+            currentUser = user;
+        }
+    }
+    
+    /**
+     * 处理密码修改
+     */
+    private void handlePasswordChange(String oldPassword, String newPassword, String confirmNewPassword) {
+        if (MathLearningAppMethods.handlePasswordChange(oldPassword, newPassword, confirmNewPassword, currentUser)) {
+            // 清空密码框
+            oldPasswordField.setText("");
+            cardLayout.show(mainPanel, "DIFFICULTY_SELECTION");
+        }
+    }
+    
+    /**
+     * 选择难度并输入题目数量
+     */
+    private void selectDifficulty(String difficulty) {
+        currentDifficulty = difficulty;
+        
+        String input = JOptionPane.showInputDialog(this, 
+            "请输入需要生成的题目数量（建议10-30题）：", 
+            "题目数量", 
+            JOptionPane.QUESTION_MESSAGE);
+        
+        if (input != null && !input.trim().isEmpty()) {
+            try {
+                int count = Integer.parseInt(input.trim());
+                if (count > 0 && count <= 50) {
+                    generateQuestions(difficulty, count);
+                } else {
+                    JOptionPane.showMessageDialog(this, "请输入1-50之间的数字！", "错误", JOptionPane.ERROR_MESSAGE);
+                }
+            } catch (NumberFormatException e) {
+                JOptionPane.showMessageDialog(this, "请输入有效的数字！", "错误", JOptionPane.ERROR_MESSAGE);
+            }
+        }
+    }
+    
+    /**
+     * 生成题目并开始答题
+     */
+    private void generateQuestions(String difficulty, int count) {
+        currentQuestions = MathLearningAppMethods.generateQuestions(difficulty, count, questionGenerator);
+        currentQuestionIndex = 0;
+        correctAnswers = 0;
+        
+        if (!currentQuestions.isEmpty()) {
+            showCurrentQuestion();
+            cardLayout.show(mainPanel, "QUESTION");
+        } else {
+            JOptionPane.showMessageDialog(this, "生成题目失败！", "错误", JOptionPane.ERROR_MESSAGE);
+        }
+    }
+
+    /**
+     * 显示当前题目
+     */
+    private void showCurrentQuestion() {
+        if (currentQuestionIndex < currentQuestions.size()) {
+            MultipleChoiceQuestion question = currentQuestions.get(currentQuestionIndex);
+
+            // 更新进度信息
+            JPanel topPanel = (JPanel) ((JPanel) mainPanel.getComponent(5)).getComponent(0);
+            JLabel progressLabel = (JLabel) topPanel.getComponent(0);
+            JLabel difficultyLabel = (JLabel) topPanel.getComponent(1);
+
+            progressLabel.setText("第 " + (currentQuestionIndex + 1) + " 题 / 共 " + currentQuestions.size() + " 题");
+            difficultyLabel.setText(currentDifficulty + "难度");
+
+            // 更新题目内容
+            questionLabel.setText("<html><center>" + question.getQuestion() + "</center></html>");
+
+            // 更新选项 - 关键修改：清除之前的选择
+            answerGroup.clearSelection(); // 清除单选按钮组的选择
+
+            String[] options = question.getOptions();
+            for (int i = 0; i < 4; i++) {
+                answerButtons[i].setText((char)('A' + i) + ". " + options[i]);
+                answerButtons[i].setSelected(false); // 确保每个按钮都是未选中状态
+            }
+
+            // 重置按钮状态
+            for (JRadioButton button : answerButtons) {
+                button.setSelected(false);
+            }
+        }
+    }
+    
+    /**
+     * 处理答案提交
+     */
+    private void handleAnswerSubmit(ActionEvent e) {
+        // 检查是否选择了答案
+        int selectedAnswer = -1;
+        for (int i = 0; i < 4; i++) {
+            if (answerButtons[i].isSelected()) {
+                selectedAnswer = i;
+                break;
+            }
+        }
+        
+        if (selectedAnswer == -1) {
+            JOptionPane.showMessageDialog(this, "请选择一个答案！", "提示", JOptionPane.WARNING_MESSAGE);
+            return;
+        }
+        
+        // 检查答案是否正确
+        MultipleChoiceQuestion currentQuestion = currentQuestions.get(currentQuestionIndex);
+        if (currentQuestion.isCorrect(selectedAnswer)) {
+            correctAnswers++;
+        }
+        
+        // 移动到下一题或显示结果
+        currentQuestionIndex++;
+        if (currentQuestionIndex < currentQuestions.size()) {
+            showCurrentQuestion();
+        } else {
+            showScore();
+        }
+    }
+    
+    /**
+     * 显示分数
+     */
+    private void showScore() {
+        int totalQuestions = currentQuestions.size();
+        double percentage = (double) correctAnswers / totalQuestions * 100;
+        
+        String scoreText = String.format("<html><center>答对 %d 题，共 %d 题<br/>正确率：%.1f%%</center></html>", 
+                                        correctAnswers, totalQuestions, percentage);
+        scoreLabel.setText(scoreText);
+        
+        cardLayout.show(mainPanel, "SCORE");
+    }
+    
+    /**
+     * 加载用户数据
+     */
+    private void loadUserData() {
+        MathLearningAppMethods.loadUserData(registeredUsers);
+    }
+    
+    /**
+     * 保存用户数据
+     */
+    private void saveUserData() {
+        MathLearningAppMethods.saveUserData(registeredUsers);
+    }
+    
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            // 直接启动程序，使用默认外观
+            new MathLearningApp().setVisible(true);
+        });
+    }
+}

src/MathLearningAppMethods.java

@@ -0,0 +1,464 @@
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.util.*;
+import java.util.List;
+import java.util.regex.Pattern;
+import java.io.*;
+import java.nio.file.*;
+
+/**
+ * MathLearningApp的方法扩展类
+ * 包含所有事件处理和工具方法
+ */
+public class MathLearningAppMethods {
+    
+    /**
+     * 创建样式化按钮
+     */
+    public static JButton createStyledButton(String text, Color backgroundColor) {
+        JButton button = new JButton(text) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变效果
+                GradientPaint gradient = new GradientPaint(0, 0, backgroundColor.brighter(), 
+                                                         0, getHeight(), backgroundColor.darker());
+                g2.setPaint(gradient);
+                g2.fillRoundRect(0, 0, getWidth(), getHeight(), 15, 15);
+                
+                // 添加内阴影效果
+                g2.setColor(new Color(0, 0, 0, 30));
+                g2.drawRoundRect(1, 1, getWidth()-3, getHeight()-3, 13, 13);
+                
+                g2.dispose();
+                super.paintComponent(g);
+            }
+        };
+        
+        button.setFont(new Font("微软雅黑", Font.BOLD, 14));
+        button.setForeground(Color.WHITE);
+        button.setFocusPainted(false);
+        button.setBorderPainted(false);
+        button.setContentAreaFilled(false);
+        button.setPreferredSize(new Dimension(130, 40));
+        button.setCursor(new Cursor(Cursor.HAND_CURSOR));
+        
+        // 添加鼠标悬停效果
+        button.addMouseListener(new java.awt.event.MouseAdapter() {
+            @Override
+            public void mouseEntered(java.awt.event.MouseEvent evt) {
+                button.setBackground(backgroundColor.brighter());
+                button.repaint();
+            }
+            
+            @Override
+            public void mouseExited(java.awt.event.MouseEvent evt) {
+                button.setBackground(backgroundColor);
+                button.repaint();
+            }
+        });
+        
+        return button;
+    }
+    
+    /**
+     * 创建大型难度选择按钮
+     */
+    public static JButton createLargeDifficultyButton(String text, Color backgroundColor) {
+        JButton button = new JButton(text) {
+            @Override
+            protected void paintComponent(Graphics g) {
+                Graphics2D g2 = (Graphics2D) g.create();
+                g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
+                
+                // 创建渐变效果
+                GradientPaint gradient = new GradientPaint(0, 0, backgroundColor.brighter(), 
+                                                         0, getHeight(), backgroundColor);
+                g2.setPaint(gradient);
+                g2.fillRoundRect(0, 0, getWidth(), getHeight(), 20, 20);
+                
+                // 添加外阴影效果
+                g2.setColor(new Color(0, 0, 0, 20));
+                g2.fillRoundRect(3, 3, getWidth(), getHeight(), 20, 20);
+                
+                // 重新绘制按钮
+                g2.setPaint(gradient);
+                g2.fillRoundRect(0, 0, getWidth()-3, getHeight()-3, 20, 20);
+                
+                // 添加边框
+                g2.setColor(backgroundColor.darker());
+                g2.setStroke(new BasicStroke(2));
+                g2.drawRoundRect(1, 1, getWidth()-5, getHeight()-5, 18, 18);
+                
+                g2.dispose();
+                super.paintComponent(g);
+            }
+        };
+        
+        button.setFont(new Font("微软雅黑", Font.BOLD, 22));
+        button.setForeground(new Color(40, 40, 40));
+        button.setFocusPainted(false);
+        button.setBorderPainted(false);
+        button.setContentAreaFilled(false);
+        button.setPreferredSize(new Dimension(320, 70));
+        button.setCursor(new Cursor(Cursor.HAND_CURSOR));
+        
+        // 添加鼠标悬停效果
+        button.addMouseListener(new java.awt.event.MouseAdapter() {
+            @Override
+            public void mouseEntered(java.awt.event.MouseEvent evt) {
+                button.setForeground(new Color(20, 20, 20));
+                button.repaint();
+            }
+            
+            @Override
+            public void mouseExited(java.awt.event.MouseEvent evt) {
+                button.setForeground(new Color(40, 40, 40));
+                button.repaint();
+            }
+        });
+        
+        return button;
+    }
+    
+    /**
+     * 发送验证码
+     */
+    public static void sendVerificationCode(ActionEvent e, JTextField emailField, Map<String, RegisteredUser> registeredUsers) {
+        String email = emailField.getText().trim();
+        
+        if (!isValidEmail(email)) {
+            JOptionPane.showMessageDialog(null, "请输入有效的邮箱地址！", "错误", JOptionPane.ERROR_MESSAGE);
+            return;
+        }
+        
+        // 检查邮箱是否已完成注册（验证码验证成功且设置了密码）
+        RegisteredUser existingUser = registeredUsers.get(email);
+        if (existingUser != null && existingUser.isVerified() && existingUser.getPassword() != null) {
+            JOptionPane.showMessageDialog(null, "该邮箱已注册！", "错误", JOptionPane.ERROR_MESSAGE);
+            return;
+        }
+        
+        // 生成6位验证码
+        String verificationCode = generateVerificationCode();
+        
+        // 创建或更新用户对象（仅用于临时存储验证码）
+        RegisteredUser user = new RegisteredUser(email, verificationCode);
+        registeredUsers.put(email, user);
+        
+        // 显示发送中的提示
+        JOptionPane.showMessageDialog(null, 
+            "正在通过QQ邮箱发送验证码到您的邮箱，请稍候...", 
+            "发送中", 
+            JOptionPane.INFORMATION_MESSAGE);
+        
+        // 在后台线程发送邮件，避免阻塞UI
+        new Thread(() -> {
+            boolean success = QQEmailService.sendVerificationCode(email, verificationCode);
+            
+            // 在EDT线程中显示结果
+            javax.swing.SwingUtilities.invokeLater(() -> {
+                if (success) {
+                    JOptionPane.showMessageDialog(null, 
+                        "✅ 验证码已通过QQ邮箱发送！\n" +
+                        "📧 请查收邮件并输入6位验证码。\n" +
+                        "📱 如果没收到，请检查垃圾邮件文件夹。", 
+                        "发送成功", 
+                        JOptionPane.INFORMATION_MESSAGE);
+                } else {
+                    JOptionPane.showMessageDialog(null, 
+                        "❌ 验证码发送失败！\n" +
+                        "请检查：\n" +
+                        "• 接收邮箱地址是否正确\n" +
+                        "• QQ邮箱配置是否正确\n" +
+                        "• 网络连接是否正常", 
+                        "发送失败", 
+                        JOptionPane.ERROR_MESSAGE);
+                    // 发送失败时移除用户
+                    registeredUsers.remove(email);
+                }
+            });
+        }).start();
+    }
+    
+    /**
+     * 处理用户注册
+     */
+    public static boolean handleRegister(JTextField emailField, JTextField verificationCodeField, 
+                                       Map<String, RegisteredUser> registeredUsers, CardLayout cardLayout, JPanel mainPanel) {
+        String email = emailField.getText().trim();
+        String code = verificationCodeField.getText().trim();
+        
+        if (email.isEmpty() || code.isEmpty()) {
+            JOptionPane.showMessageDialog(null, "请填写完整信息！", "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        RegisteredUser user = registeredUsers.get(email);
+        if (user == null) {
+            JOptionPane.showMessageDialog(null, "请先发送验证码！", "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        if (!user.verifyCode(code)) {
+            JOptionPane.showMessageDialog(null, "验证码错误！", "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        user.setVerified(true);
+        JOptionPane.showMessageDialog(null, "注册成功！请设置密码。", "成功", JOptionPane.INFORMATION_MESSAGE);
+        cardLayout.show(mainPanel, "PASSWORD_SETUP");
+        return true;
+    }
+    
+    /**
+     * 处理密码设置
+     */
+    public static boolean handlePasswordSetup(JPasswordField passwordField, JPasswordField confirmPasswordField,
+                                            Map<String, RegisteredUser> registeredUsers, CardLayout cardLayout, JPanel mainPanel) {
+        String password = new String(passwordField.getPassword());
+        String confirmPassword = new String(confirmPasswordField.getPassword());
+        
+        if (!password.equals(confirmPassword)) {
+            JOptionPane.showMessageDialog(null, "两次输入的密码不一致！", "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        if (!isValidPassword(password)) {
+            JOptionPane.showMessageDialog(null, 
+                "密码不符合要求！\n要求：6-10位，必须包含大小写字母和数字", 
+                "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        // 找到当前注册的用户
+        RegisteredUser currentUser = null;
+        for (RegisteredUser user : registeredUsers.values()) {
+            if (user.isVerified() && user.getPassword() == null) {
+                currentUser = user;
+                break;
+            }
+        }
+        
+        if (currentUser != null) {
+            currentUser.setPassword(password);
+            saveUserData(registeredUsers);
+            JOptionPane.showMessageDialog(null, "密码设置成功！", "成功", JOptionPane.INFORMATION_MESSAGE);
+            cardLayout.show(mainPanel, "DIFFICULTY_SELECTION");
+            return true;
+        }
+        
+        return false;
+    }
+    
+    /**
+     * 处理用户登录
+     */
+    public static RegisteredUser handleLogin(String email, String password, 
+                                           Map<String, RegisteredUser> registeredUsers, 
+                                           CardLayout cardLayout, JPanel mainPanel) {
+        if (email.isEmpty() || password.isEmpty()) {
+            JOptionPane.showMessageDialog(null, "请填写完整信息！", "错误", JOptionPane.ERROR_MESSAGE);
+            return null;
+        }
+        
+        RegisteredUser user = registeredUsers.get(email);
+        if (user == null || !user.isVerified() || !user.verifyPassword(password)) {
+            JOptionPane.showMessageDialog(null, "用户名或密码错误！", "错误", JOptionPane.ERROR_MESSAGE);
+            return null;
+        }
+        
+        JOptionPane.showMessageDialog(null, "登录成功！", "成功", JOptionPane.INFORMATION_MESSAGE);
+        cardLayout.show(mainPanel, "DIFFICULTY_SELECTION");
+        return user;
+    }
+    
+    /**
+     * 处理密码修改
+     */
+    public static boolean handlePasswordChange(String oldPassword, String newPassword, String confirmNewPassword,
+                                             RegisteredUser currentUser) {
+        if (!currentUser.verifyPassword(oldPassword)) {
+            JOptionPane.showMessageDialog(null, "原密码错误！", "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        if (!newPassword.equals(confirmNewPassword)) {
+            JOptionPane.showMessageDialog(null, "两次输入的新密码不一致！", "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        if (!isValidPassword(newPassword)) {
+            JOptionPane.showMessageDialog(null, 
+                "新密码不符合要求！\n要求：6-10位，必须包含大小写字母和数字", 
+                "错误", JOptionPane.ERROR_MESSAGE);
+            return false;
+        }
+        
+        currentUser.setPassword(newPassword);
+        JOptionPane.showMessageDialog(null, "密码修改成功！", "成功", JOptionPane.INFORMATION_MESSAGE);
+        return true;
+    }
+    
+    /**
+     * 生成选择题
+     */
+    public static List<MultipleChoiceQuestion> generateQuestions(String difficulty, int count, MathQuestionGenerator generator) {
+        List<MultipleChoiceQuestion> questions = new ArrayList<>();
+        Random random = new Random();
+
+        int attempts = 0;
+        int maxAttempts = count * 5; // 防止无限循环
+
+        while (questions.size() < count && attempts < maxAttempts) {
+            // 生成数学表达式
+            MathQuestion mathQuestion = generateSingleQuestion(difficulty, generator);
+            String expression = mathQuestion.getExpression();
+
+            // 验证表达式语法
+            if (!ExpressionEvaluator.isValidMathExpression(expression)) {
+                attempts++;
+                continue;
+            }
+
+            // 计算正确答案
+            double correctAnswer = evaluateExpression(expression);
+
+            // 检查答案是否有效
+            if (Double.isNaN(correctAnswer) || Double.isInfinite(correctAnswer)) {
+                attempts++;
+                continue;
+            }
+
+            // 生成选项
+            String[] options = new String[4];
+            int correctIndex = random.nextInt(4);
+
+            // 设置正确答案
+            options[correctIndex] = formatAnswer(correctAnswer);
+
+            // 生成3个错误答案
+            String[] wrongAnswers = ExpressionEvaluator.generateWrongAnswers(correctAnswer, 3);
+            int wrongIndex = 0;
+            for (int j = 0; j < 4; j++) {
+                if (j != correctIndex) {
+                    options[j] = wrongAnswers[wrongIndex++];
+                }
+            }
+
+            MultipleChoiceQuestion question = new MultipleChoiceQuestion(
+                    "计算：" + expression + " = ?", options, correctIndex);
+            questions.add(question);
+            attempts = 0; // 重置尝试计数
+        }
+
+        return questions;
+    }
+    
+    /**
+     * 生成单个数学题目
+     */
+    private static MathQuestion generateSingleQuestion(String difficulty, MathQuestionGenerator generator) {
+        List<MathQuestion> questions = generator.generateQuestions(difficulty, 1);
+        return questions.get(0);
+    }
+    
+    /**
+     * 计算数学表达式的值
+     */
+    private static double evaluateExpression(String expression) {
+        return ExpressionEvaluator.evaluate(expression);
+    }
+    
+    /**
+     * 格式化答案
+     */
+    private static String formatAnswer(double answer) {
+        return ExpressionEvaluator.formatAnswer(answer);
+    }
+    
+    /**
+     * 验证邮箱格式
+     */
+    public static boolean isValidEmail(String email) {
+        String emailRegex = "^[a-zA-Z0-9_+&*-]+(?:\\.[a-zA-Z0-9_+&*-]+)*@(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,7}$";
+        Pattern pattern = Pattern.compile(emailRegex);
+        return pattern.matcher(email).matches();
+    }
+    
+    /**
+     * 验证密码格式
+     */
+    public static boolean isValidPassword(String password) {
+        if (password.length() < 6 || password.length() > 10) {
+            return false;
+        }
+        
+        boolean hasUpper = false, hasLower = false, hasDigit = false;
+        
+        for (char c : password.toCharArray()) {
+            if (Character.isUpperCase(c)) hasUpper = true;
+            else if (Character.isLowerCase(c)) hasLower = true;
+            else if (Character.isDigit(c)) hasDigit = true;
+        }
+        
+        return hasUpper && hasLower && hasDigit;
+    }
+    
+    /**
+     * 生成验证码
+     */
+    public static String generateVerificationCode() {
+        Random random = new Random();
+        StringBuilder code = new StringBuilder();
+        for (int i = 0; i < 6; i++) {
+            code.append(random.nextInt(10));
+        }
+        return code.toString();
+    }
+    
+    /**
+     * 保存用户数据
+     */
+    public static void saveUserData(Map<String, RegisteredUser> users) {
+        try {
+            Path dataFile = Paths.get("user_data.txt");
+            try (BufferedWriter writer = Files.newBufferedWriter(dataFile)) {
+                for (RegisteredUser user : users.values()) {
+                    if (user.isVerified() && user.getPassword() != null) {
+                        writer.write(user.getEmail() + ":" + user.getPassword());
+                        writer.newLine();
+                    }
+                }
+            }
+        } catch (IOException e) {
+            System.err.println("保存用户数据失败: " + e.getMessage());
+        }
+    }
+    
+    /**
+     * 加载用户数据
+     */
+    public static void loadUserData(Map<String, RegisteredUser> users) {
+        try {
+            Path dataFile = Paths.get("user_data.txt");
+            if (Files.exists(dataFile)) {
+                List<String> lines = Files.readAllLines(dataFile);
+                for (String line : lines) {
+                    String[] parts = line.split(":");
+                    if (parts.length == 2) {
+                        RegisteredUser user = new RegisteredUser(parts[0], "");
+                        user.setVerified(true);
+                        user.setPassword(parts[1]);
+                        users.put(parts[0], user);
+                    }
+                }
+            }
+        } catch (IOException e) {
+            System.err.println("加载用户数据失败: " + e.getMessage());
+        }
+    }
+}

src/QQEmailService.java

@@ -0,0 +1,218 @@
+import java.io.*;
+import java.net.*;
+import java.util.Properties;
+import java.nio.file.*;
+
+/**
+ * QQ邮箱SMTP服务
+ * 专门用于通过QQ邮箱发送验证码邮件
+ */
+public class QQEmailService {
+    
+    private static final String SMTP_HOST = "smtp.qq.com";
+    private static final String SMTP_PORT = "587";
+    private static final String CONFIG_FILE = "qq_email_config.properties";
+    
+    // 默认配置 - 直接写入程序中
+    private static String senderEmail = "1626814667@qq.com";
+    private static String senderPassword = "cjgpophigkrodhib";
+    private static String senderName = "数学学习软件";
+    
+    static {
+        // 不再需要加载配置文件，使用默认配置
+        System.out.println("使用默认QQ邮箱配置: " + senderEmail);
+    }
+    
+    /**
+     * 加载QQ邮箱配置
+     */
+    private static void loadConfig() {
+        try {
+            Path configPath = Paths.get(CONFIG_FILE);
+            if (Files.exists(configPath)) {
+                Properties props = new Properties();
+                try (InputStream input = Files.newInputStream(configPath)) {
+                    props.load(input);
+                    senderEmail = props.getProperty("qq.email", "");
+                    senderPassword = props.getProperty("qq.password", "");
+                    senderName = props.getProperty("sender.name", "数学学习软件");
+                }
+            }
+        } catch (IOException e) {
+            System.err.println("加载QQ邮箱配置失败: " + e.getMessage());
+        }
+    }
+    
+    /**
+     * 保存QQ邮箱配置
+     */
+    public static void saveConfig(String email, String password) {
+        try {
+            Properties props = new Properties();
+            props.setProperty("qq.email", email);
+            props.setProperty("qq.password", password);
+            props.setProperty("sender.name", senderName);
+            
+            try (OutputStream output = Files.newOutputStream(Paths.get(CONFIG_FILE))) {
+                props.store(output, "QQ邮箱SMTP配置 - QQ Email SMTP Configuration");
+            }
+            
+            // 更新内存中的配置
+            senderEmail = email;
+            senderPassword = password;
+            
+            System.out.println("QQ邮箱配置已保存");
+            
+        } catch (IOException e) {
+            System.err.println("保存QQ邮箱配置失败: " + e.getMessage());
+        }
+    }
+    
+    /**
+     * 检查是否已配置QQ邮箱
+     */
+    public static boolean isConfigured() {
+        // 始终返回true，因为已经有默认配置
+        return true;
+    }
+    
+    /**
+     * 获取当前配置的QQ邮箱
+     */
+    public static String getSenderEmail() {
+        return senderEmail;
+    }
+    
+    /**
+     * 发送验证码邮件
+     */
+    public static boolean sendVerificationCode(String toEmail, String verificationCode) {
+        if (!isConfigured()) {
+            System.err.println("QQ邮箱未配置！");
+            return false;
+        }
+        
+        try {
+            System.out.println("正在发送邮件...");
+            System.out.println("发送方: " + senderEmail);
+            System.out.println("接收方: " + toEmail);
+            System.out.println("验证码: " + verificationCode);
+            
+            // 使用真实的SMTP发送邮件
+            String subject = "【数学学习软件】验证码";
+            String content = RealEmailSender.createVerificationEmailContent(verificationCode);
+            
+            boolean success = RealEmailSender.sendEmail(senderEmail, senderPassword, toEmail, subject, content);
+            
+            if (success) {
+                System.out.println("邮件发送成功！");
+            } else {
+                System.out.println("邮件发送失败！");
+            }
+            
+            return success;
+            
+        } catch (Exception e) {
+            System.err.println("发送邮件失败: " + e.getMessage());
+            e.printStackTrace();
+            return false;
+        }
+    }
+    
+    /**
+     * 通过SMTP发送邮件（简化实现）
+     */
+    private static boolean sendEmailViaSMTP(String toEmail, String verificationCode) {
+        try {
+            // 创建Socket连接到QQ SMTP服务器
+            Socket socket = new Socket(SMTP_HOST, Integer.parseInt(SMTP_PORT));
+            
+            BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+            PrintWriter writer = new PrintWriter(socket.getOutputStream(), true);
+            
+            // 读取服务器欢迎信息
+            String response = reader.readLine();
+            System.out.println("服务器响应: " + response);
+            
+            // SMTP握手过程
+            writer.println("EHLO localhost");
+            response = reader.readLine();
+            System.out.println("EHLO响应: " + response);
+            
+            // 启动TLS加密
+            writer.println("STARTTLS");
+            response = reader.readLine();
+            System.out.println("STARTTLS响应: " + response);
+            
+            // 这里需要升级到SSL连接，但为了简化，我们使用HTTP API方式
+            socket.close();
+            
+            // 改用HTTP API方式发送（模拟）
+            return sendViaHTTPAPI(toEmail, verificationCode);
+            
+        } catch (Exception e) {
+            System.err.println("SMTP连接失败: " + e.getMessage());
+            return sendViaHTTPAPI(toEmail, verificationCode);
+        }
+    }
+    
+    /**
+     * 通过HTTP API发送邮件（模拟实现）
+     */
+    private static boolean sendViaHTTPAPI(String toEmail, String verificationCode) {
+        try {
+            System.out.println("=== QQ邮箱发送邮件 ===");
+            System.out.println("发送方: " + senderEmail);
+            System.out.println("接收方: " + toEmail);
+            System.out.println("验证码: " + verificationCode);
+            System.out.println("邮件内容: " + createEmailContent(verificationCode));
+            System.out.println("===================");
+            
+            // 模拟发送延迟
+            Thread.sleep(1000);
+            
+            // 在实际项目中，这里应该调用真实的SMTP库或HTTP API
+            // 例如使用JavaMail库或第三方邮件服务API
+            
+            return true;
+            
+        } catch (Exception e) {
+            e.printStackTrace();
+            return false;
+        }
+    }
+    
+    /**
+     * 创建邮件内容
+     */
+    private static String createEmailContent(String verificationCode) {
+        return "【数学学习软件】验证码\n\n" +
+               "您的注册验证码是：" + verificationCode + "\n\n" +
+               "验证码有效期为10分钟，请及时使用。\n" +
+               "如果您没有注册我们的软件，请忽略此邮件。\n\n" +
+               "此邮件由系统自动发送，请勿回复。";
+    }
+    
+    /**
+     * 测试QQ邮箱连接
+     */
+    public static boolean testConnection() {
+        if (!isConfigured()) {
+            return false;
+        }
+        
+        try {
+            // 测试连接到QQ SMTP服务器
+            Socket socket = new Socket();
+            socket.connect(new InetSocketAddress(SMTP_HOST, Integer.parseInt(SMTP_PORT)), 5000);
+            socket.close();
+            
+            System.out.println("QQ SMTP服务器连接测试成功");
+            return true;
+            
+        } catch (Exception e) {
+            System.err.println("QQ SMTP服务器连接测试失败: " + e.getMessage());
+            return false;
+        }
+    }
+}

src/RealEmailSender.java

@@ -0,0 +1,176 @@
+import java.io.*;
+import java.net.*;
+import java.util.Base64;
+import javax.net.ssl.*;
+
+/**
+ * 真实的邮件发送器
+ * 使用原生Java实现SMTP协议发送邮件
+ */
+public class RealEmailSender {
+    
+    private static final String SMTP_HOST = "smtp.qq.com";
+    private static final int SMTP_PORT = 587;
+    
+    /**
+     * 发送邮件
+     */
+    public static boolean sendEmail(String fromEmail, String fromPassword, String toEmail, String subject, String content) {
+        try {
+            // 1. 连接到SMTP服务器
+            Socket socket = new Socket(SMTP_HOST, SMTP_PORT);
+            BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
+            PrintWriter writer = new PrintWriter(socket.getOutputStream(), true);
+            
+            // 2. 读取服务器欢迎信息
+            String response = reader.readLine();
+            System.out.println("服务器: " + response);
+            if (!response.startsWith("220")) {
+                throw new Exception("SMTP服务器连接失败");
+            }
+            
+            // 3. 发送EHLO命令
+            writer.println("EHLO localhost");
+            response = readMultiLineResponse(reader);
+            System.out.println("EHLO响应: " + response);
+            
+            // 4. 启动TLS加密
+            writer.println("STARTTLS");
+            response = reader.readLine();
+            System.out.println("STARTTLS响应: " + response);
+            if (!response.startsWith("220")) {
+                throw new Exception("启动TLS失败");
+            }
+            
+            // 5. 升级到SSL连接
+            SSLSocketFactory factory = (SSLSocketFactory) SSLSocketFactory.getDefault();
+            SSLSocket sslSocket = (SSLSocket) factory.createSocket(socket, SMTP_HOST, SMTP_PORT, true);
+            sslSocket.startHandshake();
+            
+            // 6. 重新创建读写器
+            reader = new BufferedReader(new InputStreamReader(sslSocket.getInputStream()));
+            writer = new PrintWriter(sslSocket.getOutputStream(), true);
+            
+            // 7. 重新发送EHLO
+            writer.println("EHLO localhost");
+            response = readMultiLineResponse(reader);
+            System.out.println("SSL EHLO响应: " + response);
+            
+            // 8. 认证
+            writer.println("AUTH LOGIN");
+            response = reader.readLine();
+            System.out.println("AUTH响应: " + response);
+            if (!response.startsWith("334")) {
+                throw new Exception("认证失败");
+            }
+            
+            // 9. 发送用户名（Base64编码）
+            String encodedUsername = Base64.getEncoder().encodeToString(fromEmail.getBytes());
+            writer.println(encodedUsername);
+            response = reader.readLine();
+            System.out.println("用户名响应: " + response);
+            if (!response.startsWith("334")) {
+                throw new Exception("用户名认证失败");
+            }
+            
+            // 10. 发送密码（Base64编码）
+            String encodedPassword = Base64.getEncoder().encodeToString(fromPassword.getBytes());
+            writer.println(encodedPassword);
+            response = reader.readLine();
+            System.out.println("密码响应: " + response);
+            if (!response.startsWith("235")) {
+                throw new Exception("密码认证失败: " + response);
+            }
+            
+            // 11. 发送邮件
+            // MAIL FROM
+            writer.println("MAIL FROM:<" + fromEmail + ">");
+            response = reader.readLine();
+            System.out.println("MAIL FROM响应: " + response);
+            if (!response.startsWith("250")) {
+                throw new Exception("MAIL FROM失败");
+            }
+            
+            // RCPT TO
+            writer.println("RCPT TO:<" + toEmail + ">");
+            response = reader.readLine();
+            System.out.println("RCPT TO响应: " + response);
+            if (!response.startsWith("250")) {
+                throw new Exception("RCPT TO失败");
+            }
+            
+            // DATA
+            writer.println("DATA");
+            response = reader.readLine();
+            System.out.println("DATA响应: " + response);
+            if (!response.startsWith("354")) {
+                throw new Exception("DATA失败");
+            }
+            
+            // 邮件头和内容
+            writer.println("From: " + fromEmail);
+            writer.println("To: " + toEmail);
+            writer.println("Subject: =?UTF-8?B?" + Base64.getEncoder().encodeToString(subject.getBytes("UTF-8")) + "?=");
+            writer.println("MIME-Version: 1.0");
+            writer.println("Content-Type: text/plain; charset=UTF-8");
+            writer.println("Content-Transfer-Encoding: base64");
+            writer.println("X-Mailer: MathLearningSystem");
+            writer.println("X-Priority: 1");
+            writer.println();
+            writer.println(Base64.getEncoder().encodeToString(content.getBytes("UTF-8")));
+            writer.println(".");
+            
+            response = reader.readLine();
+            System.out.println("邮件发送响应: " + response);
+            if (!response.startsWith("250")) {
+                throw new Exception("邮件发送失败");
+            }
+            
+            // 12. 退出
+            writer.println("QUIT");
+            response = reader.readLine();
+            System.out.println("QUIT响应: " + response);
+            
+            // 13. 关闭连接
+            sslSocket.close();
+            
+            System.out.println("邮件发送成功！");
+            return true;
+            
+        } catch (Exception e) {
+            System.err.println("邮件发送失败: " + e.getMessage());
+            e.printStackTrace();
+            return false;
+        }
+    }
+    
+    /**
+     * 读取多行响应
+     */
+    private static String readMultiLineResponse(BufferedReader reader) throws IOException {
+        StringBuilder response = new StringBuilder();
+        String line;
+        while ((line = reader.readLine()) != null) {
+            response.append(line).append("\n");
+            // 如果行不是以'-'结尾，说明是最后一行
+            if (line.length() >= 4 && line.charAt(3) != '-') {
+                break;
+            }
+        }
+        return response.toString();
+    }
+    
+    /**
+     * 创建验证码邮件内容
+     */
+    public static String createVerificationEmailContent(String verificationCode) {
+        return "您好！\n\n" +
+               "您正在注册数学学习软件，您的验证码是：\n\n" +
+               "验证码：" + verificationCode + "\n\n" +
+               "验证码有效期为10分钟，请及时使用。\n" +
+               "如果您没有注册我们的软件，请忽略此邮件。\n\n" +
+               "祝您学习愉快！\n" +
+               "数学学习软件团队\n\n" +
+               "此邮件由系统自动发送，请勿回复。";
+    }
+}

src/RegisteredUser.java

@@ -0,0 +1,56 @@
+/**
+ * 注册用户类
+ * 存储用户注册信息和密码
+ */
+public class RegisteredUser {
+    private String email;
+    private String password;
+    private String verificationCode;
+    private boolean isVerified;
+    
+    public RegisteredUser(String email, String verificationCode) {
+        this.email = email;
+        this.verificationCode = verificationCode;
+        this.isVerified = false;
+    }
+    
+    public String getEmail() {
+        return email;
+    }
+    
+    public String getPassword() {
+        return password;
+    }
+    
+    public void setPassword(String password) {
+        this.password = password;
+    }
+    
+    public String getVerificationCode() {
+        return verificationCode;
+    }
+    
+    public boolean isVerified() {
+        return isVerified;
+    }
+    
+    public void setVerified(boolean verified) {
+        isVerified = verified;
+    }
+    
+    public boolean verifyCode(String code) {
+        return verificationCode.equals(code);
+    }
+    
+    public boolean verifyPassword(String password) {
+        return this.password != null && this.password.equals(password);
+    }
+    
+    @Override
+    public String toString() {
+        return "RegisteredUser{" +
+                "email='" + email + '\'' +
+                ", isVerified=" + isVerified +
+                '}';
+    }
+}