Flutter学习打卡助手应用开发教程

项目简介

这是一款功能完整的学习打卡助手应用，帮助用户养成良好的学习习惯。应用采用Material Design 3设计风格，支持任务管理、打卡记录、统计分析、日历视图等功能，界面美观，操作简便。
运行效果图

核心特性

• 任务管理：创建、编辑、删除学习任务
• 打卡功能：每日打卡，记录学习进度
• 连续打卡：自动计算连续打卡天数
• 进度追踪：可视化显示任务完成进度
• 分类管理：英语、编程、阅读、运动、写作五大分类
• 统计分析：总打卡次数、最长连续、完成任务数
• 日历视图：月历展示打卡记录
• 任务详情：查看详细的打卡历史
• 渐变设计：精美的渐变UI设计

技术栈

• Flutter 3.x
• Material Design 3
• 状态管理（setState）
• 日期时间处理
• 数据持久化（可扩展）

项目架构

数据模型设计

StudyTask（学习任务模型）

class StudyTask {
  final int id;                      // 任务ID
  String title;                      // 任务标题（可修改）
  final String category;             // 分类
  int targetDays;                    // 目标天数（可修改）
  int currentStreak;                 // 当前连续天数
  int totalDays;                     // 总打卡天数
  final DateTime startDate;          // 开始日期
  DateTime? lastCheckInDate;         // 最后打卡日期
  final List<DateTime> checkInDates; // 打卡日期列表
  bool isCompleted;                  // 是否完成
  
  bool get canCheckInToday;          // 今天是否可以打卡
  double get progress;               // 完成进度（0.0-1.0）
}

设计要点：

• ID用于唯一标识
• title和targetDays可修改（编辑功能）
• currentStreak自动计算连续天数
• checkInDates记录所有打卡日期
• canCheckInToday防止重复打卡
• progress计算完成百分比

任务分类

分类	图标	颜色	示例任务
英语	language	蓝色	每日英语单词、英语口语
编程	code	紫色	Flutter学习、Python算法
阅读	book	橙色	阅读30分钟
运动	fitness_center	绿色	晨跑打卡、健身训练
写作	edit	粉色	写作练习

打卡状态判断

bool get canCheckInToday {
  if (lastCheckInDate == null) return true;
  final today = DateTime.now();
  return lastCheckInDate!.year != today.year ||
      lastCheckInDate!.month != today.month ||
      lastCheckInDate!.day != today.day;
}

逻辑说明：

• 从未打卡：可以打卡
• 最后打卡日期不是今天：可以打卡
• 最后打卡日期是今天：不可打卡

核心功能实现

1. 打卡功能

打卡是应用的核心功能，需要处理多个逻辑。

void _checkIn(StudyTask task) {
  // 检查今天是否已打卡
  if (!task.canCheckInToday) {
    ScaffoldMessenger.of(context).showSnackBar(
      const SnackBar(content: Text('今天已经打卡过了')),
    );
    return;
  }

  setState(() {
    final now = DateTime.now();
    // 添加打卡记录
    task.checkInDates.add(now);
    task.lastCheckInDate = now;
    task.totalDays++;
    
    // 计算连续天数
    if (task.lastCheckInDate != null) {
      final yesterday = now.subtract(const Duration(days: 1));
      final lastCheckIn = task.lastCheckInDate!;
      if (lastCheckIn.year == yesterday.year &&
          lastCheckIn.month == yesterday.month &&
          lastCheckIn.day == yesterday.day) {
        task.currentStreak++;  // 连续打卡
      } else {
        task.currentStreak = 1;  // 重新开始
      }
    } else {
      task.currentStreak = 1;
    }
    
    // 检查是否完成目标
    if (task.totalDays >= task.targetDays) {
      task.isCompleted = true;
    }
  });

  ScaffoldMessenger.of(context).showSnackBar(
    SnackBar(
      content: Text('打卡成功！连续${task.currentStreak}天'),
      backgroundColor: Colors.green,
    ),
  );
}

打卡逻辑：

1. 检查今天是否已打卡
2. 记录打卡时间
3. 更新总天数
4. 计算连续天数（昨天打卡则+1，否则重置为1）
5. 检查是否达成目标
6. 显示成功提示

2. 任务卡片设计

任务卡片展示任务的关键信息和操作按钮。

Widget _buildTaskCard(StudyTask task) {
  return Card(
    margin: const EdgeInsets.only(bottom: 12),
    child: InkWell(
      onTap: () {
        Navigator.push(
          context,
          MaterialPageRoute(
            builder: (context) => TaskDetailPage(task: task),
          ),
        );
      },
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            // 头部：图标、标题、完成标识
            Row(
              children: [
                Container(
                  padding: const EdgeInsets.all(8),
                  decoration: BoxDecoration(
                    color: _getCategoryColor(task.category).withValues(alpha: 0.1),
                    borderRadius: BorderRadius.circular(8),
                  ),
                  child: Icon(
                    _getCategoryIcon(task.category),
                    color: _getCategoryColor(task.category),
                    size: 24,
                  ),
                ),
                const SizedBox(width: 12),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(task.title, style: TextStyle(fontWeight: FontWeight.bold)),
                      Text(task.category, style: TextStyle(color: Colors.grey)),
                    ],
                  ),
                ),
                if (task.isCompleted)
                  Container(
                    padding: EdgeInsets.symmetric(horizontal: 8, vertical: 4),
                    decoration: BoxDecoration(
                      color: Colors.green.shade50,
                      borderRadius: BorderRadius.circular(12),
                    ),
                    child: Text('已完成', style: TextStyle(color: Colors.green)),
                  ),
              ],
            ),
            // 统计信息
            Row(
              children: [
                Icon(Icons.local_fire_department, size: 16, color: Colors.orange),
                Text('连续${task.currentStreak}天'),
                Icon(Icons.check_circle, size: 16, color: Colors.green),
                Text('已打卡${task.totalDays}天'),
              ],
            ),
            // 进度条和打卡按钮
            Row(
              children: [
                Expanded(
                  child: LinearProgressIndicator(
                    value: task.progress.clamp(0.0, 1.0),
                    backgroundColor: Colors.grey.shade200,
                  ),
                ),
                ElevatedButton(
                  onPressed: task.canCheckInToday ? () => _checkIn(task) : null,
                  child: Text(task.canCheckInToday ? '打卡' : '已打卡'),
                ),
              ],
            ),
          ],
        ),
      ),
    ),
  );
}

3. 统计页面

统计页面展示学习数据的汇总分析。

Widget _buildStatisticsPage() {
  final totalCheckIns = _tasks.fold<int>(0, (sum, task) => sum + task.totalDays);
  final maxStreak = _tasks.fold<int>(0, (max, task) => 
      task.currentStreak > max ? task.currentStreak : max);
  final completedTasks = _tasks.where((t) => t.isCompleted).length;
  
  return Column(
    children: [
      // 头部
      Container(
        decoration: BoxDecoration(
          gradient: LinearGradient(
            colors: [Colors.indigo.shade600, Colors.indigo.shade400],
          ),
        ),
        child: Text('学习统计', style: TextStyle(color: Colors.white)),
      ),
      // 统计卡片
      Row(
        children: [
          _buildStatisticCard('总打卡', '$totalCheckIns', '次', 
                             Icons.check_circle, Colors.green),
          _buildStatisticCard('最长连续', '$maxStreak', '天', 
                             Icons.local_fire_department, Colors.orange),
        ],
      ),
      Row(
        children: [
          _buildStatisticCard('已完成', '$completedTasks', '个', 
                             Icons.emoji_events, Colors.amber),
          _buildStatisticCard('进行中', '${_tasks.length - completedTasks}', '个', 
                             Icons.pending_actions, Colors.blue),
        ],
      ),
      // 分类统计
      _buildCategoryStatistics(),
    ],
  );
}

统计指标：

• 总打卡：所有任务的打卡总次数
• 最长连续：所有任务中最长的连续天数
• 已完成：达成目标的任务数量
• 进行中：未完成的任务数量

4. 分类统计

展示各分类的打卡天数对比。

Widget _buildCategoryStatistics() {
  final categoryStats = <String, int>{};
  for (final task in _tasks) {
    categoryStats[task.category] = 
        (categoryStats[task.category] ?? 0) + task.totalDays;
  }

  return Card(
    child: Column(
      children: [
        Text('分类统计', style: TextStyle(fontWeight: FontWeight.bold)),
        ...categoryStats.entries.map((entry) {
          final maxValue = categoryStats.values.reduce((a, b) => a > b ? a : b);
          final percentage = entry.value / maxValue;
          return Column(
            children: [
              Row(
                children: [
                  Icon(_getCategoryIcon(entry.key)),
                  Text(entry.key),
                  Spacer(),
                  Text('${entry.value}天'),
                ],
              ),
              LinearProgressIndicator(value: percentage),
            ],
          );
        }),
      ],
    ),
  );
}

5. 日历视图

月历展示打卡记录，直观显示学习轨迹。

Widget _buildCalendarPage() {
  final now = DateTime.now();
  final firstDayOfMonth = DateTime(now.year, now.month, 1);
  final daysInMonth = DateTime(now.year, now.month + 1, 0).day;
  final firstWeekday = firstDayOfMonth.weekday;

  return Column(
    children: [
      // 头部
      Container(
        decoration: BoxDecoration(
          gradient: LinearGradient(
            colors: [Colors.indigo.shade600, Colors.indigo.shade400],
          ),
        ),
        child: Column(
          children: [
            Text('打卡日历', style: TextStyle(color: Colors.white)),
            Text('${now.year}年${now.month}月', 
                 style: TextStyle(color: Colors.white70)),
          ],
        ),
      ),
      // 星期标题
      Row(
        children: ['日', '一', '二', '三', '四', '五', '六'].map((day) {
          return SizedBox(
            width: 40,
            child: Center(child: Text(day)),
          );
        }).toList(),
      ),
      // 日期网格
      GridView.builder(
        gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
          crossAxisCount: 7,
          mainAxisSpacing: 8,
          crossAxisSpacing: 8,
        ),
        itemCount: daysInMonth + firstWeekday % 7,
        itemBuilder: (context, index) {
          if (index < firstWeekday % 7) {
            return SizedBox();  // 空白占位
          }
          
          final day = index - firstWeekday % 7 + 1;
          final date = DateTime(now.year, now.month, day);
          final hasCheckIn = _tasks.any((task) => 
            task.checkInDates.any((d) => 
              d.year == date.year && 
              d.month == date.month && 
              d.day == date.day
            )
          );
          final isToday = date.year == now.year && 
                          date.month == now.month && 
                          date.day == now.day;

          return Container(
            decoration: BoxDecoration(
              color: hasCheckIn ? Colors.indigo.shade100 : Colors.grey.shade100,
              borderRadius: BorderRadius.circular(8),
              border: isToday ? Border.all(color: Colors.indigo, width: 2) : null,
            ),
            child: Column(
              children: [
                Text('$day'),
                if (hasCheckIn) Icon(Icons.check_circle, size: 12),
              ],
            ),
          );
        },
      ),
    ],
  );
}

日历特点：

• 显示当前月份
• 有打卡的日期高亮显示
• 今天用边框标识
• 打卡日期显示勾选图标

6. 添加任务对话框

使用对话框创建新任务。

void _showAddTaskDialog() {
  final titleController = TextEditingController();
  String selectedCategory = '英语';
  int targetDays = 30;

  showDialog(
    context: context,
    builder: (context) {
      return StatefulBuilder(
        builder: (context, setDialogState) {
          return AlertDialog(
            title: Text('添加新任务'),
            content: SingleChildScrollView(
              child: Column(
                children: [
                  // 任务名称输入
                  TextField(
                    controller: titleController,
                    decoration: InputDecoration(
                      labelText: '任务名称',
                      border: OutlineInputBorder(),
                    ),
                  ),
                  // 分类选择
                  DropdownButtonFormField<String>(
                    value: selectedCategory,
                    decoration: InputDecoration(
                      labelText: '分类',
                      border: OutlineInputBorder(),
                    ),
                    items: ['英语', '编程', '阅读', '运动', '写作'].map((category) {
                      return DropdownMenuItem(
                        value: category,
                        child: Row(
                          children: [
                            Icon(_getCategoryIcon(category), size: 20),
                            Text(category),
                          ],
                        ),
                      );
                    }).toList(),
                    onChanged: (value) {
                      setDialogState(() {
                        selectedCategory = value!;
                      });
                    },
                  ),
                  // 目标天数滑块
                  Row(
                    children: [
                      Text('目标天数：'),
                      Expanded(
                        child: Slider(
                          value: targetDays.toDouble(),
                          min: 7,
                          max: 365,
                          divisions: 50,
                          label: '$targetDays天',
                          onChanged: (value) {
                            setDialogState(() {
                              targetDays = value.toInt();
                            });
                          },
                        ),
                      ),
                      Text('$targetDays天'),
                    ],
                  ),
                ],
              ),
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.pop(context),
                child: Text('取消'),
              ),
              ElevatedButton(
                onPressed: () {
                  if (titleController.text.isNotEmpty) {
                    setState(() {
                      _tasks.add(StudyTask(
                        id: _tasks.length + 1,
                        title: titleController.text,
                        category: selectedCategory,
                        targetDays: targetDays,
                        startDate: DateTime.now(),
                      ));
                    });
                    Navigator.pop(context);
                  }
                },
                child: Text('添加'),
              ),
            ],
          );
        },
      );
    },
  );
}

对话框特点：

• 使用StatefulBuilder实现对话框内状态更新
• 文本输入框输入任务名称
• 下拉菜单选择分类
• 滑块选择目标天数（7-365天）

7. 任务详情页面

展示任务的详细信息和打卡历史。

class TaskDetailPage extends StatefulWidget {
  final StudyTask task;
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('任务详情'),
        actions: [
          IconButton(icon: Icon(Icons.edit), onPressed: _editTask),
          IconButton(icon: Icon(Icons.delete), onPressed: _deleteTask),
        ],
      ),
      body: SingleChildScrollView(
        child: Column(
          children: [
            _buildHeader(),
            _buildProgressCard(),
            _buildCheckInHistory(),
          ],
        ),
      ),
    );
  }
}

详情页头部：

Widget _buildHeader() {
  return Container(
    decoration: BoxDecoration(
      gradient: LinearGradient(
        colors: [
          _getCategoryColor(_task.category).withValues(alpha: 0.8),
          _getCategoryColor(_task.category),
        ],
      ),
    ),
    child: Column(
      children: [
        Icon(_getCategoryIcon(_task.category), size: 60, color: Colors.white),
        Text(_task.title, style: TextStyle(color: Colors.white, fontSize: 24)),
        Container(
          decoration: BoxDecoration(
            color: Colors.white.withValues(alpha: 0.2),
            borderRadius: BorderRadius.circular(16),
          ),
          child: Text(_task.category, style: TextStyle(color: Colors.white)),
        ),
      ],
    ),
  );
}

进度卡片：

Widget _buildProgressCard() {
  return Card(
    child: Column(
      children: [
        Text('学习进度', style: TextStyle(fontWeight: FontWeight.bold)),
        Row(
          children: [
            _buildStatItem('已打卡', '${_task.totalDays}天', 
                          Icons.check_circle, Colors.green),
            _buildStatItem('连续', '${_task.currentStreak}天', 
                          Icons.local_fire_department, Colors.orange),
            _buildStatItem('目标', '${_task.targetDays}天', 
                          Icons.flag, Colors.blue),
          ],
        ),
        Row(
          children: [
            Text('完成度'),
            Text('${(_task.progress * 100).toStringAsFixed(1)}%'),
          ],
        ),
        LinearProgressIndicator(
          value: _task.progress.clamp(0.0, 1.0),
          minHeight: 12,
        ),
      ],
    ),
  );
}

打卡历史：

Widget _buildCheckInHistory() {
  final sortedDates = List<DateTime>.from(_task.checkInDates)
    ..sort((a, b) => b.compareTo(a));  // 降序排列

  return Card(
    child: Column(
      children: [
        Text('打卡历史', style: TextStyle(fontWeight: FontWeight.bold)),
        if (sortedDates.isEmpty)
          Text('还没有打卡记录')
        else
          ...sortedDates.take(10).map((date) {
            return ListTile(
              leading: Icon(Icons.check_circle),
              title: Text(_formatDate(date)),
              subtitle: Text(_formatTime(date)),
            );
          }),
      ],
    ),
  );
}

8. 编辑和删除功能

编辑任务：

void _editTask() {
  final titleController = TextEditingController(text: _task.title);
  int targetDays = _task.targetDays;

  showDialog(
    context: context,
    builder: (context) {
      return StatefulBuilder(
        builder: (context, setDialogState) {
          return AlertDialog(
            title: Text('编辑任务'),
            content: Column(
              children: [
                TextField(
                  controller: titleController,
                  decoration: InputDecoration(
                    labelText: '任务名称',
                    border: OutlineInputBorder(),
                  ),
                ),
                Row(
                  children: [
                    Text('目标天数：'),
                    Slider(
                      value: targetDays.toDouble(),
                      min: 7,
                      max: 365,
                      onChanged: (value) {
                        setDialogState(() {
                          targetDays = value.toInt();
                        });
                      },
                    ),
                    Text('$targetDays天'),
                  ],
                ),
              ],
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.pop(context),
                child: Text('取消'),
              ),
              ElevatedButton(
                onPressed: () {
                  setState(() {
                    _task.title = titleController.text;
                    _task.targetDays = targetDays;
                  });
                  Navigator.pop(context);
                },
                child: Text('保存'),
              ),
            ],
          );
        },
      );
    },
  );
}

删除任务：

void _deleteTask() {
  showDialog(
    context: context,
    builder: (context) {
      return AlertDialog(
        title: Text('删除任务'),
        content: Text('确定要删除这个任务吗？删除后无法恢复。'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context),
            child: Text('取消'),
          ),
          ElevatedButton(
            onPressed: () {
              Navigator.pop(context);
              Navigator.pop(context, true);  // 返回上一页
              ScaffoldMessenger.of(context).showSnackBar(
                SnackBar(content: Text('任务已删除'), backgroundColor: Colors.red),
              );
            },
            style: ElevatedButton.styleFrom(
              backgroundColor: Colors.red,
              foregroundColor: Colors.white,
            ),
            child: Text('删除'),
          ),
        ],
      );
    },
  );
}

UI组件设计

1. 渐变头部

Container(
  padding: const EdgeInsets.fromLTRB(16, 48, 16, 16),
  decoration: BoxDecoration(
    gradient: LinearGradient(
      colors: [Colors.indigo.shade600, Colors.indigo.shade400],
      begin: Alignment.topLeft,
      end: Alignment.bottomRight,
    ),
  ),
  child: Column(
    children: [
      Row(
        children: [
          Icon(Icons.school, color: Colors.white, size: 32),
          Text('学习打卡助手', style: TextStyle(color: Colors.white, fontSize: 24)),
        ],
      ),
      Row(
        children: [
          _buildStatCard('今日打卡', '$todayCheckIns/$totalTasks', Icons.check_circle),
          _buildStatCard('总任务', '$totalTasks', Icons.task_alt),
        ],
      ),
    ],
  ),
)

2. 统计卡片

Widget _buildStatCard(String label, String value, IconData icon) {
  return Container(
    padding: const EdgeInsets.all(16),
    decoration: BoxDecoration(
      color: Colors.white.withValues(alpha: 0.2),
      borderRadius: BorderRadius.circular(12),
    ),
    child: Column(
      children: [
        Icon(icon, color: Colors.white70, size: 20),
        Text(value, style: TextStyle(color: Colors.white, fontSize: 24)),
        Text(label, style: TextStyle(color: Colors.white70, fontSize: 12)),
      ],
    ),
  );
}

3. 分类筛选标签

Widget _buildCategoryFilter() {
  return Container(
    height: 50,
    child: ListView(
      scrollDirection: Axis.horizontal,
      children: [
        _buildCategoryChip('全部', Icons.apps),
        _buildCategoryChip('英语', Icons.language),
        _buildCategoryChip('编程', Icons.code),
        _buildCategoryChip('阅读', Icons.book),
        _buildCategoryChip('运动', Icons.fitness_center),
        _buildCategoryChip('写作', Icons.edit),
      ],
    ),
  );
}

Widget _buildCategoryChip(String label, IconData icon) {
  return Container(
    margin: const EdgeInsets.only(right: 8),
    child: FilterChip(
      label: Row(
        children: [
          Icon(icon, size: 16),
          Text(label),
        ],
      ),
      selected: false,
      onSelected: (selected) {},
    ),
  );
}

4. NavigationBar底部导航

NavigationBar(
  selectedIndex: _selectedIndex,
  onDestinationSelected: (index) {
    setState(() {
      _selectedIndex = index;
    });
  },
  destinations: const [
    NavigationDestination(
      icon: Icon(Icons.task_outlined),
      selectedIcon: Icon(Icons.task),
      label: '任务',
    ),
    NavigationDestination(
      icon: Icon(Icons.bar_chart_outlined),
      selectedIcon: Icon(Icons.bar_chart),
      label: '统计',
    ),
    NavigationDestination(
      icon: Icon(Icons.calendar_month_outlined),
      selectedIcon: Icon(Icons.calendar_month),
      label: '日历',
    ),
  ],
)

功能扩展建议

1. 数据持久化

使用shared_preferences或sqflite保存数据。

import 'package:shared_preferences/shared_preferences.dart';
import 'dart:convert';

class TaskStorage {
  static const String _key = 'study_tasks';
  
  // 保存任务列表
  static Future<void> saveTasks(List<StudyTask> tasks) async {
    final prefs = await SharedPreferences.getInstance();
    final jsonList = tasks.map((task) => task.toJson()).toList();
    await prefs.setString(_key, json.encode(jsonList));
  }
  
  // 加载任务列表
  static Future<List<StudyTask>> loadTasks() async {
    final prefs = await SharedPreferences.getInstance();
    final jsonString = prefs.getString(_key);
    if (jsonString == null) return [];
    
    final List<dynamic> jsonList = json.decode(jsonString);
    return jsonList.map((json) => StudyTask.fromJson(json)).toList();
  }
}

// 在StudyTask类中添加序列化方法
class StudyTask {
  // ... 现有代码 ...
  
  Map<String, dynamic> toJson() {
    return {
      'id': id,
      'title': title,
      'category': category,
      'targetDays': targetDays,
      'currentStreak': currentStreak,
      'totalDays': totalDays,
      'startDate': startDate.toIso8601String(),
      'lastCheckInDate': lastCheckInDate?.toIso8601String(),
      'checkInDates': checkInDates.map((d) => d.toIso8601String()).toList(),
      'isCompleted': isCompleted,
    };
  }
  
  factory StudyTask.fromJson(Map<String, dynamic> json) {
    return StudyTask(
      id: json['id'],
      title: json['title'],
      category: json['category'],
      targetDays: json['targetDays'],
      currentStreak: json['currentStreak'],
      totalDays: json['totalDays'],
      startDate: DateTime.parse(json['startDate']),
      lastCheckInDate: json['lastCheckInDate'] != null 
          ? DateTime.parse(json['lastCheckInDate']) 
          : null,
      checkInDates: (json['checkInDates'] as List)
          .map((d) => DateTime.parse(d))
          .toList(),
      isCompleted: json['isCompleted'],
    );
  }
}

// 在_StudyHomePageState中使用
@override
void initState() {
  super.initState();
  _loadTasks();
}

Future<void> _loadTasks() async {
  final tasks = await TaskStorage.loadTasks();
  setState(() {
    _tasks = tasks;
  });
}

void _saveTasks() {
  TaskStorage.saveTasks(_tasks);
}

// 在每次修改任务后调用_saveTasks()
void _checkIn(StudyTask task) {
  // ... 打卡逻辑 ...
  _saveTasks();
}

2. 打卡提醒

使用flutter_local_notifications设置每日提醒。

import 'package:flutter_local_notifications/flutter_local_notifications.dart';

class NotificationService {
  static final FlutterLocalNotificationsPlugin _notifications = 
      FlutterLocalNotificationsPlugin();
  
  static Future<void> init() async {
    const androidSettings = AndroidInitializationSettings('@mipmap/ic_launcher');
    const iosSettings = DarwinInitializationSettings();
    const settings = InitializationSettings(
      android: androidSettings,
      iOS: iosSettings,
    );
    
    await _notifications.initialize(settings);
  }
  
  static Future<void> scheduleDailyReminder({
    required int hour,
    required int minute,
  }) async {
    await _notifications.zonedSchedule(
      0,
      '学习打卡提醒',
      '今天还没有打卡哦，快来完成你的学习任务吧！',
      _nextInstanceOfTime(hour, minute),
      const NotificationDetails(
        android: AndroidNotificationDetails(
          'daily_reminder',
          '每日提醒',
          importance: Importance.high,
          priority: Priority.high,
        ),
      ),
      androidScheduleMode: AndroidScheduleMode.exactAllowWhileIdle,
      uiLocalNotificationDateInterpretation:
          UILocalNotificationDateInterpretation.absoluteTime,
      matchDateTimeComponents: DateTimeComponents.time,
    );
  }
  
  static TZDateTime _nextInstanceOfTime(int hour, int minute) {
    final now = TZDateTime.now(local);
    var scheduledDate = TZDateTime(local, now.year, now.month, now.day, hour, minute);
    
    if (scheduledDate.isBefore(now)) {
      scheduledDate = scheduledDate.add(const Duration(days: 1));
    }
    
    return scheduledDate;
  }
}

// 在设置页面添加提醒时间选择
class SettingsPage extends StatefulWidget {
  @override
  State<SettingsPage> createState() => _SettingsPageState();
}

class _SettingsPageState extends State<SettingsPage> {
  TimeOfDay _reminderTime = const TimeOfDay(hour: 20, minute: 0);
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('设置')),
      body: ListView(
        children: [
          ListTile(
            leading: const Icon(Icons.notifications),
            title: const Text('每日提醒'),
            subtitle: Text('${_reminderTime.hour}:${_reminderTime.minute}'),
            onTap: () async {
              final time = await showTimePicker(
                context: context,
                initialTime: _reminderTime,
              );
              if (time != null) {
                setState(() {
                  _reminderTime = time;
                });
                await NotificationService.scheduleDailyReminder(
                  hour: time.hour,
                  minute: time.minute,
                );
              }
            },
          ),
        ],
      ),
    );
  }
}

3. 成就系统

添加成就徽章激励用户。

class Achievement {
  final String id;
  final String title;
  final String description;
  final IconData icon;
  final Color color;
  final bool Function(List<StudyTask> tasks) condition;
  
  Achievement({
    required this.id,
    required this.title,
    required this.description,
    required this.icon,
    required this.color,
    required this.condition,
  });
}

class AchievementService {
  static final List<Achievement> achievements = [
    Achievement(
      id: 'first_checkin',
      title: '初次打卡',
      description: '完成第一次打卡',
      icon: Icons.star,
      color: Colors.amber,
      condition: (tasks) => tasks.any((t) => t.totalDays >= 1),
    ),
    Achievement(
      id: 'week_streak',
      title: '坚持一周',
      description: '连续打卡7天',
      icon: Icons.local_fire_department,
      color: Colors.orange,
      condition: (tasks) => tasks.any((t) => t.currentStreak >= 7),
    ),
    Achievement(
      id: 'month_streak',
      title: '坚持一月',
      description: '连续打卡30天',
      icon: Icons.emoji_events,
      color: Colors.purple,
      condition: (tasks) => tasks.any((t) => t.currentStreak >= 30),
    ),
    Achievement(
      id: 'complete_task',
      title: '完成目标',
      description: '完成一个学习任务',
      icon: Icons.check_circle,
      color: Colors.green,
      condition: (tasks) => tasks.any((t) => t.isCompleted),
    ),
    Achievement(
      id: 'complete_five',
      title: '学习达人',
      description: '完成5个学习任务',
      icon: Icons.school,
      color: Colors.blue,
      condition: (tasks) => tasks.where((t) => t.isCompleted).length >= 5,
    ),
    Achievement(
      id: 'hundred_days',
      title: '百日坚持',
      description: '累计打卡100天',
      icon: Icons.military_tech,
      color: Colors.red,
      condition: (tasks) => 
          tasks.fold<int>(0, (sum, t) => sum + t.totalDays) >= 100,
    ),
  ];
  
  static List<Achievement> getUnlockedAchievements(List<StudyTask> tasks) {
    return achievements.where((a) => a.condition(tasks)).toList();
  }
  
  static List<Achievement> getLockedAchievements(List<StudyTask> tasks) {
    return achievements.where((a) => !a.condition(tasks)).toList();
  }
}

// 成就页面
class AchievementsPage extends StatelessWidget {
  final List<StudyTask> tasks;
  
  const AchievementsPage({required this.tasks});
  
  @override
  Widget build(BuildContext context) {
    final unlocked = AchievementService.getUnlockedAchievements(tasks);
    final locked = AchievementService.getLockedAchievements(tasks);
    
    return Scaffold(
      appBar: AppBar(title: const Text('成就')),
      body: ListView(
        padding: const EdgeInsets.all(16),
        children: [
          Text('已解锁 (${unlocked.length}/${AchievementService.achievements.length})',
               style: const TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
          const SizedBox(height: 16),
          ...unlocked.map((achievement) => _buildAchievementCard(achievement, true)),
          const SizedBox(height: 24),
          const Text('未解锁', style: TextStyle(fontSize: 18, fontWeight: FontWeight.bold)),
          const SizedBox(height: 16),
          ...locked.map((achievement) => _buildAchievementCard(achievement, false)),
        ],
      ),
    );
  }
  
  Widget _buildAchievementCard(Achievement achievement, bool unlocked) {
    return Card(
      child: ListTile(
        leading: Container(
          padding: const EdgeInsets.all(12),
          decoration: BoxDecoration(
            color: unlocked 
                ? achievement.color.withValues(alpha: 0.2) 
                : Colors.grey.shade200,
            shape: BoxShape.circle,
          ),
          child: Icon(
            achievement.icon,
            color: unlocked ? achievement.color : Colors.grey,
          ),
        ),
        title: Text(
          achievement.title,
          style: TextStyle(
            color: unlocked ? Colors.black : Colors.grey,
            fontWeight: FontWeight.bold,
          ),
        ),
        subtitle: Text(
          achievement.description,
          style: TextStyle(color: unlocked ? Colors.grey.shade700 : Colors.grey),
        ),
        trailing: unlocked 
            ? Icon(Icons.check_circle, color: achievement.color)
            : Icon(Icons.lock, color: Colors.grey),
      ),
    );
  }
}

4. 数据导出

导出学习数据为CSV或JSON格式。

import 'dart:io';
import 'package:path_provider/path_provider.dart';
import 'package:share_plus/share_plus.dart';

class DataExporter {
  // 导出为CSV
  static Future<void> exportToCSV(List<StudyTask> tasks) async {
    final buffer = StringBuffer();
    buffer.writeln('任务名称,分类,目标天数,已打卡天数,连续天数,完成状态,开始日期');
    
    for (final task in tasks) {
      buffer.writeln(
        '${task.title},${task.category},${task.targetDays},'
        '${task.totalDays},${task.currentStreak},'
        '${task.isCompleted ? "已完成" : "进行中"},'
        '${task.startDate.toString().split(' ')[0]}'
      );
    }
    
    final directory = await getApplicationDocumentsDirectory();
    final file = File('${directory.path}/study_tasks_${DateTime.now().millisecondsSinceEpoch}.csv');
    await file.writeAsString(buffer.toString());
    
    await Share.shareXFiles([XFile(file.path)], text: '学习打卡数据');
  }
  
  // 导出为JSON
  static Future<void> exportToJSON(List<StudyTask> tasks) async {
    final jsonData = {
      'export_date': DateTime.now().toIso8601String(),
      'total_tasks': tasks.length,
      'completed_tasks': tasks.where((t) => t.isCompleted).length,
      'tasks': tasks.map((t) => t.toJson()).toList(),
    };
    
    final jsonString = const JsonEncoder.withIndent('  ').convert(jsonData);
    
    final directory = await getApplicationDocumentsDirectory();
    final file = File('${directory.path}/study_tasks_${DateTime.now().millisecondsSinceEpoch}.json');
    await file.writeAsString(jsonString);
    
    await Share.shareXFiles([XFile(file.path)], text: '学习打卡数据');
  }
  
  // 生成统计报告
  static Future<void> exportReport(List<StudyTask> tasks) async {
    final totalCheckIns = tasks.fold<int>(0, (sum, t) => sum + t.totalDays);
    final maxStreak = tasks.fold<int>(0, (max, t) => 
        t.currentStreak > max ? t.currentStreak : max);
    final completedTasks = tasks.where((t) => t.isCompleted).length;
    
    final buffer = StringBuffer();
    buffer.writeln('学习打卡统计报告');
    buffer.writeln('生成时间: ${DateTime.now()}');
    buffer.writeln('');
    buffer.writeln('总体统计:');
    buffer.writeln('- 总任务数: ${tasks.length}');
    buffer.writeln('- 已完成: $completedTasks');
    buffer.writeln('- 进行中: ${tasks.length - completedTasks}');
    buffer.writeln('- 总打卡次数: $totalCheckIns');
    buffer.writeln('- 最长连续: $maxStreak天');
    buffer.writeln('');
    buffer.writeln('任务详情:');
    
    for (final task in tasks) {
      buffer.writeln('');
      buffer.writeln('【${task.title}】');
      buffer.writeln('  分类: ${task.category}');
      buffer.writeln('  进度: ${task.totalDays}/${task.targetDays}天 (${(task.progress * 100).toStringAsFixed(1)}%)');
      buffer.writeln('  连续: ${task.currentStreak}天');
      buffer.writeln('  状态: ${task.isCompleted ? "已完成" : "进行中"}');
    }
    
    final directory = await getApplicationDocumentsDirectory();
    final file = File('${directory.path}/study_report_${DateTime.now().millisecondsSinceEpoch}.txt');
    await file.writeAsString(buffer.toString());
    
    await Share.shareXFiles([XFile(file.path)], text: '学习统计报告');
  }
}

// 在设置页面添加导出选项
ListTile(
  leading: const Icon(Icons.download),
  title: const Text('导出数据'),
  subtitle: const Text('导出为CSV或JSON格式'),
  onTap: () {
    showDialog(
      context: context,
      builder: (context) {
        return AlertDialog(
          title: const Text('选择导出格式'),
          content: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              ListTile(
                leading: const Icon(Icons.table_chart),
                title: const Text('CSV格式'),
                onTap: () {
                  Navigator.pop(context);
                  DataExporter.exportToCSV(_tasks);
                },
              ),
              ListTile(
                leading: const Icon(Icons.code),
                title: const Text('JSON格式'),
                onTap: () {
                  Navigator.pop(context);
                  DataExporter.exportToJSON(_tasks);
                },
              ),
              ListTile(
                leading: const Icon(Icons.description),
                title: const Text('统计报告'),
                onTap: () {
                  Navigator.pop(context);
                  DataExporter.exportReport(_tasks);
                },
              ),
            ],
          ),
        );
      },
    );
  },
),

5. 学习小组

创建学习小组，与好友一起打卡。

class StudyGroup {
  final String id;
  final String name;
  final String description;
  final List<String> memberIds;
  final DateTime createdAt;
  
  StudyGroup({
    required this.id,
    required this.name,
    required this.description,
    required this.memberIds,
    required this.createdAt,
  });
}

class GroupMember {
  final String id;
  final String name;
  final String avatar;
  final int totalCheckIns;
  final int currentStreak;
  
  GroupMember({
    required this.id,
    required this.name,
    required this.avatar,
    required this.totalCheckIns,
    required this.currentStreak,
  });
}

class StudyGroupPage extends StatefulWidget {
  @override
  State<StudyGroupPage> createState() => _StudyGroupPageState();
}

class _StudyGroupPageState extends State<StudyGroupPage> {
  List<StudyGroup> _groups = [];
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('学习小组')),
      body: ListView.builder(
        itemCount: _groups.length,
        itemBuilder: (context, index) {
          final group = _groups[index];
          return Card(
            child: ListTile(
              leading: CircleAvatar(
                child: Text(group.name[0]),
              ),
              title: Text(group.name),
              subtitle: Text('${group.memberIds.length}名成员'),
              trailing: const Icon(Icons.arrow_forward_ios),
              onTap: () {
                Navigator.push(
                  context,
                  MaterialPageRoute(
                    builder: (context) => GroupDetailPage(group: group),
                  ),
                );
              },
            ),
          );
        },
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _createGroup,
        child: const Icon(Icons.add),
      ),
    );
  }
  
  void _createGroup() {
    // 创建小组对话框
  }
}

class GroupDetailPage extends StatelessWidget {
  final StudyGroup group;
  
  const GroupDetailPage({required this.group});
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(group.name)),
      body: Column(
        children: [
          _buildGroupInfo(),
          _buildMemberRanking(),
          _buildGroupActivity(),
        ],
      ),
    );
  }
  
  Widget _buildGroupInfo() {
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          children: [
            Text(group.name, style: const TextStyle(fontSize: 20, fontWeight: FontWeight.bold)),
            const SizedBox(height: 8),
            Text(group.description),
            const SizedBox(height: 16),
            Row(
              mainAxisAlignment: MainAxisAlignment.spaceAround,
              children: [
                Column(
                  children: [
                    const Icon(Icons.people),
                    Text('${group.memberIds.length}'),
                    const Text('成员'),
                  ],
                ),
                Column(
                  children: [
                    const Icon(Icons.check_circle),
                    const Text('1234'),
                    const Text('总打卡'),
                  ],
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
  
  Widget _buildMemberRanking() {
    // 成员排行榜
    return Card(
      child: Column(
        children: [
          const Text('成员排行', style: TextStyle(fontWeight: FontWeight.bold)),
          // 排行榜列表
        ],
      ),
    );
  }
  
  Widget _buildGroupActivity() {
    // 小组动态
    return Card(
      child: Column(
        children: [
          const Text('小组动态', style: TextStyle(fontWeight: FontWeight.bold)),
          // 动态列表
        ],
      ),
    );
  }
}

6. 学习笔记

为每次打卡添加学习笔记。

class CheckInNote {
  final DateTime date;
  final String content;
  final List<String> tags;
  final int mood;  // 1-5星心情
  
  CheckInNote({
    required this.date,
    required this.content,
    required this.tags,
    required this.mood,
  });
}

// 在StudyTask中添加笔记列表
class StudyTask {
  // ... 现有字段 ...
  final List<CheckInNote> notes;
  
  StudyTask({
    // ... 现有参数 ...
    List<CheckInNote>? notes,
  }) : notes = notes ?? [];
}

// 打卡时添加笔记
void _checkInWithNote(StudyTask task) {
  final noteController = TextEditingController();
  int mood = 3;
  
  showDialog(
    context: context,
    builder: (context) {
      return StatefulBuilder(
        builder: (context, setDialogState) {
          return AlertDialog(
            title: const Text('打卡笔记'),
            content: SingleChildScrollView(
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  TextField(
                    controller: noteController,
                    maxLines: 5,
                    decoration: const InputDecoration(
                      hintText: '记录今天的学习心得...',
                      border: OutlineInputBorder(),
                    ),
                  ),
                  const SizedBox(height: 16),
                  const Text('今天的心情'),
                  Row(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: List.generate(5, (index) {
                      return IconButton(
                        icon: Icon(
                          index < mood ? Icons.star : Icons.star_border,
                          color: Colors.amber,
                        ),
                        onPressed: () {
                          setDialogState(() {
                            mood = index + 1;
                          });
                        },
                      );
                    }),
                  ),
                ],
              ),
            ),
            actions: [
              TextButton(
                onPressed: () => Navigator.pop(context),
                child: const Text('取消'),
              ),
              ElevatedButton(
                onPressed: () {
                  setState(() {
                    final now = DateTime.now();
                    task.checkInDates.add(now);
                    task.lastCheckInDate = now;
                    task.totalDays++;
                    
                    if (noteController.text.isNotEmpty) {
                      task.notes.add(CheckInNote(
                        date: now,
                        content: noteController.text,
                        tags: [],
                        mood: mood,
                      ));
                    }
                  });
                  Navigator.pop(context);
                  ScaffoldMessenger.of(context).showSnackBar(
                    const SnackBar(content: Text('打卡成功'), backgroundColor: Colors.green),
                  );
                },
                child: const Text('打卡'),
              ),
            ],
          );
        },
      );
    },
  );
}

// 笔记列表页面
class NotesPage extends StatelessWidget {
  final StudyTask task;
  
  const NotesPage({required this.task});
  
  @override
  Widget build(BuildContext context) {
    final sortedNotes = List<CheckInNote>.from(task.notes)
      ..sort((a, b) => b.date.compareTo(a.date));
    
    return Scaffold(
      appBar: AppBar(title: const Text('学习笔记')),
      body: ListView.builder(
        itemCount: sortedNotes.length,
        itemBuilder: (context, index) {
          final note = sortedNotes[index];
          return Card(
            margin: const EdgeInsets.all(8),
            child: Padding(
              padding: const EdgeInsets.all(16),
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Row(
                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
                    children: [
                      Text(
                        _formatDate(note.date),
                        style: const TextStyle(fontWeight: FontWeight.bold),
                      ),
                      Row(
                        children: List.generate(5, (i) {
                          return Icon(
                            i < note.mood ? Icons.star : Icons.star_border,
                            size: 16,
                            color: Colors.amber,
                          );
                        }),
                      ),
                    ],
                  ),
                  const SizedBox(height: 8),
                  Text(note.content),
                ],
              ),
            ),
          );
        },
      ),
    );
  }
  
  String _formatDate(DateTime date) {
    return '${date.year}年${date.month}月${date.day}日';
  }
}

7. 数据可视化

使用fl_chart展示学习趋势。

import 'package:fl_chart/fl_chart.dart';

class StatisticsChartPage extends StatelessWidget {
  final List<StudyTask> tasks;
  
  const StatisticsChartPage({required this.tasks});
  
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('数据分析')),
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Column(
          children: [
            _buildWeeklyChart(),
            const SizedBox(height: 24),
            _buildCategoryPieChart(),
            const SizedBox(height: 24),
            _buildStreakLineChart(),
          ],
        ),
      ),
    );
  }
  
  Widget _buildWeeklyChart() {
    // 最近7天打卡统计
    final now = DateTime.now();
    final weekData = List.generate(7, (index) {
      final date = now.subtract(Duration(days: 6 - index));
      final count = tasks.fold<int>(0, (sum, task) {
        return sum + task.checkInDates.where((d) =>
          d.year == date.year &&
          d.month == date.month &&
          d.day == date.day
        ).length;
      });
      return count;
    });
    
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text('最近7天打卡', style: TextStyle(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            SizedBox(
              height: 200,
              child: BarChart(
                BarChartData(
                  alignment: BarChartAlignment.spaceAround,
                  maxY: weekData.reduce((a, b) => a > b ? a : b).toDouble() + 2,
                  barGroups: List.generate(7, (index) {
                    return BarChartGroupData(
                      x: index,
                      barRods: [
                        BarChartRodData(
                          toY: weekData[index].toDouble(),
                          color: Colors.indigo,
                          width: 20,
                          borderRadius: BorderRadius.circular(4),
                        ),
                      ],
                    );
                  }),
                  titlesData: FlTitlesData(
                    bottomTitles: AxisTitles(
                      sideTitles: SideTitles(
                        showTitles: true,
                        getTitlesWidget: (value, meta) {
                          const days = ['一', '二', '三', '四', '五', '六', '日'];
                          return Text(days[value.toInt()]);
                        },
                      ),
                    ),
                    leftTitles: AxisTitles(
                      sideTitles: SideTitles(showTitles: true),
                    ),
                    topTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
                    rightTitles: AxisTitles(sideTitles: SideTitles(showTitles: false)),
                  ),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
  
  Widget _buildCategoryPieChart() {
    // 分类占比饼图
    final categoryStats = <String, int>{};
    for (final task in tasks) {
      categoryStats[task.category] = 
          (categoryStats[task.category] ?? 0) + task.totalDays;
    }
    
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text('分类占比', style: TextStyle(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            SizedBox(
              height: 200,
              child: PieChart(
                PieChartData(
                  sections: categoryStats.entries.map((entry) {
                    final total = categoryStats.values.reduce((a, b) => a + b);
                    final percentage = (entry.value / total * 100).toStringAsFixed(1);
                    return PieChartSectionData(
                      value: entry.value.toDouble(),
                      title: '${entry.key}\n$percentage%',
                      color: _getCategoryColor(entry.key),
                      radius: 80,
                    );
                  }).toList(),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
  
  Widget _buildStreakLineChart() {
    // 连续打卡趋势折线图
    return Card(
      child: Padding(
        padding: const EdgeInsets.all(16),
        child: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text('连续打卡趋势', style: TextStyle(fontWeight: FontWeight.bold)),
            const SizedBox(height: 16),
            SizedBox(
              height: 200,
              child: LineChart(
                LineChartData(
                  lineBarsData: tasks.map((task) {
                    return LineChartBarData(
                      spots: List.generate(task.checkInDates.length, (index) {
                        return FlSpot(index.toDouble(), (index + 1).toDouble());
                      }),
                      isCurved: true,
                      color: _getCategoryColor(task.category),
                      barWidth: 2,
                      dotData: FlDotData(show: false),
                    );
                  }).toList(),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
  
  Color _getCategoryColor(String category) {
    switch (category) {
      case '英语': return Colors.blue;
      case '编程': return Colors.purple;
      case '阅读': return Colors.orange;
      case '运动': return Colors.green;
      case '写作': return Colors.pink;
      default: return Colors.grey;
    }
  }
}

8. 番茄钟计时

集成番茄工作法计时器。

class PomodoroTimer extends StatefulWidget {
  final StudyTask task;
  
  const PomodoroTimer({required this.task});
  
  @override
  State<PomodoroTimer> createState() => _PomodoroTimerState();
}

class _PomodoroTimerState extends State<PomodoroTimer> {
  static const int workDuration = 25 * 60;  // 25分钟
  static const int breakDuration = 5 * 60;  // 5分钟
  
  int _remainingSeconds = workDuration;
  bool _isWorking = true;
  bool _isRunning = false;
  Timer? _timer;
  int _completedPomodoros = 0;
  
  @override
  void dispose() {
    _timer?.cancel();
    super.dispose();
  }
  
  void _startTimer() {
    setState(() {
      _isRunning = true;
    });
    
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      setState(() {
        if (_remainingSeconds > 0) {
          _remainingSeconds--;
        } else {
          _onTimerComplete();
        }
      });
    });
  }
  
  void _pauseTimer() {
    _timer?.cancel();
    setState(() {
      _isRunning = false;
    });
  }
  
  void _resetTimer() {
    _timer?.cancel();
    setState(() {
      _isRunning = false;
      _remainingSeconds = _isWorking ? workDuration : breakDuration;
    });
  }
  
  void _onTimerComplete() {
    _timer?.cancel();
    
    if (_isWorking) {
      _completedPomodoros++;
      // 播放提示音
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('工作时间结束，休息一下吧！'),
          backgroundColor: Colors.green,
        ),
      );
    } else {
      ScaffoldMessenger.of(context).showSnackBar(
        const SnackBar(
          content: Text('休息结束，继续加油！'),
          backgroundColor: Colors.blue,
        ),
      );
    }
    
    setState(() {
      _isWorking = !_isWorking;
      _remainingSeconds = _isWorking ? workDuration : breakDuration;
      _isRunning = false;
    });
  }
  
  @override
  Widget build(BuildContext context) {
    final minutes = _remainingSeconds ~/ 60;
    final seconds = _remainingSeconds % 60;
    
    return Scaffold(
      appBar: AppBar(title: Text(widget.task.title)),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            Text(
              _isWorking ? '工作时间' : '休息时间',
              style: TextStyle(
                fontSize: 24,
                color: _isWorking ? Colors.red : Colors.green,
                fontWeight: FontWeight.bold,
              ),
            ),
            const SizedBox(height: 32),
            Container(
              width: 250,
              height: 250,
              decoration: BoxDecoration(
                shape: BoxShape.circle,
                border: Border.all(
                  color: _isWorking ? Colors.red : Colors.green,
                  width: 8,
                ),
              ),
              child: Center(
                child: Text(
                  '${minutes.toString().padLeft(2, '0')}:${seconds.toString().padLeft(2, '0')}',
                  style: const TextStyle(
                    fontSize: 64,
                    fontWeight: FontWeight.bold,
                  ),
                ),
              ),
            ),
            const SizedBox(height: 32),
            Row(
              mainAxisAlignment: MainAxisAlignment.center,
              children: [
                ElevatedButton.icon(
                  onPressed: _isRunning ? _pauseTimer : _startTimer,
                  icon: Icon(_isRunning ? Icons.pause : Icons.play_arrow),
                  label: Text(_isRunning ? '暂停' : '开始'),
                  style: ElevatedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(horizontal: 32, vertical: 16),
                  ),
                ),
                const SizedBox(width: 16),
                ElevatedButton.icon(
                  onPressed: _resetTimer,
                  icon: const Icon(Icons.refresh),
                  label: const Text('重置'),
                  style: ElevatedButton.styleFrom(
                    padding: const EdgeInsets.symmetric(horizontal: 32, vertical: 16),
                  ),
                ),
              ],
            ),
            const SizedBox(height: 32),
            Text(
              '已完成 $_completedPomodoros 个番茄钟',
              style: const TextStyle(fontSize: 18),
            ),
          ],
        ),
      ),
    );
  }
}

性能优化建议

1. 列表优化

使用ListView.builder而非ListView，避免一次性渲染所有任务。

// 好的做法
ListView.builder(
  itemCount: _tasks.length,
  itemBuilder: (context, index) {
    return _buildTaskCard(_tasks[index]);
  },
)

// 避免
ListView(
  children: _tasks.map((task) => _buildTaskCard(task)).toList(),
)

2. 状态管理优化

对于大型应用，考虑使用Provider或Riverpod进行状态管理。

import 'package:provider/provider.dart';

class TaskProvider extends ChangeNotifier {
  List<StudyTask> _tasks = [];
  
  List<StudyTask> get tasks => _tasks;
  
  void addTask(StudyTask task) {
    _tasks.add(task);
    notifyListeners();
    _saveTasks();
  }
  
  void checkIn(StudyTask task) {
    // 打卡逻辑
    notifyListeners();
    _saveTasks();
  }
  
  Future<void> _saveTasks() async {
    await TaskStorage.saveTasks(_tasks);
  }
}

// 在main.dart中使用
void main() {
  runApp(
    ChangeNotifierProvider(
      create: (context) => TaskProvider(),
      child: const StudyCheckInApp(),
    ),
  );
}

// 在Widget中使用
class _StudyHomePageState extends State<StudyHomePage> {
  @override
  Widget build(BuildContext context) {
    final taskProvider = Provider.of<TaskProvider>(context);
    
    return ListView.builder(
      itemCount: taskProvider.tasks.length,
      itemBuilder: (context, index) {
        return _buildTaskCard(taskProvider.tasks[index]);
      },
    );
  }
}

3. 图片缓存

如果添加了用户头像等图片功能，使用cached_network_image。

import 'package:cached_network_image/cached_network_image.dart';

CachedNetworkImage(
  imageUrl: user.avatarUrl,
  placeholder: (context, url) => CircularProgressIndicator(),
  errorWidget: (context, url, error) => Icon(Icons.person),
)

4. 懒加载

对于打卡历史等长列表，实现分页加载。

class _TaskDetailPageState extends State<TaskDetailPage> {
  final ScrollController _scrollController = ScrollController();
  int _displayedNotes = 10;
  
  @override
  void initState() {
    super.initState();
    _scrollController.addListener(_onScroll);
  }
  
  void _onScroll() {
    if (_scrollController.position.pixels >= 
        _scrollController.position.maxScrollExtent * 0.9) {
      setState(() {
        _displayedNotes = min(_displayedNotes + 10, widget.task.notes.length);
      });
    }
  }
  
  @override
  Widget build(BuildContext context) {
    final notes = widget.task.notes.take(_displayedNotes).toList();
    
    return ListView.builder(
      controller: _scrollController,
      itemCount: notes.length,
      itemBuilder: (context, index) {
        return _buildNoteCard(notes[index]);
      },
    );
  }
}

测试建议

1. 单元测试

测试核心业务逻辑。

import 'package:flutter_test/flutter_test.dart';

void main() {
  group('StudyTask Tests', () {
    test('canCheckInToday returns true for new task', () {
      final task = StudyTask(
        id: 1,
        title: '测试任务',
        category: '英语',
        targetDays: 30,
        startDate: DateTime.now(),
      );
      
      expect(task.canCheckInToday, true);
    });
    
    test('canCheckInToday returns false after check-in today', () {
      final task = StudyTask(
        id: 1,
        title: '测试任务',
        category: '英语',
        targetDays: 30,
        startDate: DateTime.now(),
        lastCheckInDate: DateTime.now(),
      );
      
      expect(task.canCheckInToday, false);
    });
    
    test('progress calculation is correct', () {
      final task = StudyTask(
        id: 1,
        title: '测试任务',
        category: '英语',
        targetDays: 100,
        totalDays: 50,
        startDate: DateTime.now(),
      );
      
      expect(task.progress, 0.5);
    });
    
    test('task is completed when reaching target', () {
      final task = StudyTask(
        id: 1,
        title: '测试任务',
        category: '英语',
        targetDays: 10,
        totalDays: 10,
        startDate: DateTime.now(),
        isCompleted: true,
      );
      
      expect(task.isCompleted, true);
    });
  });
  
  group('Check-in Logic Tests', () {
    test('consecutive check-in increases streak', () {
      final task = StudyTask(
        id: 1,
        title: '测试任务',
        category: '英语',
        targetDays: 30,
        startDate: DateTime.now().subtract(const Duration(days: 1)),
        lastCheckInDate: DateTime.now().subtract(const Duration(days: 1)),
        currentStreak: 1,
      );
      
      // 模拟今天打卡
      task.lastCheckInDate = DateTime.now();
      task.currentStreak++;
      
      expect(task.currentStreak, 2);
    });
    
    test('non-consecutive check-in resets streak', () {
      final task = StudyTask(
        id: 1,
        title: '测试任务',
        category: '英语',
        targetDays: 30,
        startDate: DateTime.now().subtract(const Duration(days: 5)),
        lastCheckInDate: DateTime.now().subtract(const Duration(days: 3)),
        currentStreak: 5,
      );
      
      // 模拟今天打卡（中间断了）
      task.lastCheckInDate = DateTime.now();
      task.currentStreak = 1;
      
      expect(task.currentStreak, 1);
    });
  });
}

2. Widget测试

测试UI组件。

import 'package:flutter_test/flutter_test.dart';
import 'package:flutter/material.dart';

void main() {
  testWidgets('Task card displays correct information', (tester) async {
    final task = StudyTask(
      id: 1,
      title: '测试任务',
      category: '英语',
      targetDays: 30,
      totalDays: 10,
      currentStreak: 5,
      startDate: DateTime.now(),
    );
    
    await tester.pumpWidget(
      MaterialApp(
        home: Scaffold(
          body: _buildTaskCard(task),
        ),
      ),
    );
    
    expect(find.text('测试任务'), findsOneWidget);
    expect(find.text('英语'), findsOneWidget);
    expect(find.text('连续5天'), findsOneWidget);
    expect(find.text('已打卡10天'), findsOneWidget);
  });
  
  testWidgets('Check-in button is disabled after check-in', (tester) async {
    final task = StudyTask(
      id: 1,
      title: '测试任务',
      category: '英语',
      targetDays: 30,
      startDate: DateTime.now(),
      lastCheckInDate: DateTime.now(),
    );
    
    await tester.pumpWidget(
      MaterialApp(
        home: Scaffold(
          body: _buildTaskCard(task),
        ),
      ),
    );
    
    final button = find.text('已打卡');
    expect(button, findsOneWidget);
    
    // 验证按钮是禁用状态
    final elevatedButton = tester.widget<ElevatedButton>(
      find.byType(ElevatedButton),
    );
    expect(elevatedButton.onPressed, null);
  });
}

3. 集成测试

测试完整的用户流程。

import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();
  
  testWidgets('Complete check-in flow', (tester) async {
    await tester.pumpWidget(const StudyCheckInApp());
    
    // 等待应用加载
    await tester.pumpAndSettle();
    
    // 点击添加任务按钮
    await tester.tap(find.byIcon(Icons.add));
    await tester.pumpAndSettle();
    
    // 输入任务名称
    await tester.enterText(find.byType(TextField), '集成测试任务');
    
    // 点击添加按钮
    await tester.tap(find.text('添加'));
    await tester.pumpAndSettle();
    
    // 验证任务已添加
    expect(find.text('集成测试任务'), findsOneWidget);
    
    // 点击打卡按钮
    await tester.tap(find.text('打卡'));
    await tester.pumpAndSettle();
    
    // 验证打卡成功提示
    expect(find.text('打卡成功！连续1天'), findsOneWidget);
    
    // 验证按钮变为已打卡
    expect(find.text('已打卡'), findsOneWidget);
  });
}

部署指南

1. Android打包

# 生成签名密钥
keytool -genkey -v -keystore ~/key.jks -keyalg RSA -keysize 2048 -validity 10000 -alias key

# 配置android/key.properties
storePassword=<密码>
keyPassword=<密码>
keyAlias=key
storeFile=<密钥文件路径>

# 构建APK
flutter build apk --release

# 构建App Bundle（推荐用于Google Play）
flutter build appbundle --release

2. iOS打包

# 安装CocoaPods依赖
cd ios
pod install
cd ..

# 构建iOS应用
flutter build ios --release

# 在Xcode中打开项目进行签名和上传
open ios/Runner.xcworkspace

3. 应用图标

使用flutter_launcher_icons生成各平台图标。

# pubspec.yaml
dev_dependencies:
  flutter_launcher_icons: ^0.13.1

flutter_launcher_icons:
  android: true
  ios: true
  image_path: "assets/icon/app_icon.png"
  adaptive_icon_background: "#FFFFFF"
  adaptive_icon_foreground: "assets/icon/app_icon_foreground.png"

# 生成图标
flutter pub run flutter_launcher_icons

4. 应用名称

Android (android/app/src/main/AndroidManifest.xml):

<application
    android:label="学习打卡助手"
    ...>

iOS (ios/Runner/Info.plist):

<key>CFBundleName</key>
<string>学习打卡助手</string>
<key>CFBundleDisplayName</key>
<string>学习打卡</string>

5. 版本管理

在pubspec.yaml中管理版本号：

version: 1.0.0+1
# 格式：主版本.次版本.修订号+构建号

6. 混淆配置

Android (android/app/build.gradle):

buildTypes {
    release {
        signingConfig signingConfigs.release
        minifyEnabled true
        shrinkResources true
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

项目总结

技术亮点

1. 完整的打卡系统：支持每日打卡、连续天数计算、防重复打卡
2. 多维度统计：总打卡、最长连续、分类统计等多角度数据分析
3. 日历视图：直观展示打卡记录，一目了然
4. 任务管理：创建、编辑、删除任务，灵活管理学习计划
5. 进度追踪：实时显示任务完成进度，激励持续学习
6. 分类系统：五大学习分类，支持筛选和统计
7. Material Design 3：采用最新设计规范，界面美观现代
8. 渐变设计：精美的渐变UI，提升视觉体验
9. 状态管理：合理的状态管理，保证数据一致性
10. 可扩展性：预留扩展接口，易于添加新功能

学习收获

通过本项目，你将掌握：

• 日期时间处理：DateTime的使用、日期比较、日历生成
• 状态管理：setState的使用、数据流管理
• 列表操作：fold、where、map等高阶函数
• 对话框：AlertDialog、StatefulBuilder的使用
• 导航：页面跳转、参数传递、返回值处理
• UI设计：渐变、卡片、进度条、网格布局
• 数据持久化：本地存储方案（可扩展）
• 用户体验：防重复操作、即时反馈、空状态处理

应用场景

本应用适用于：

• 学生：记录每日学习任务，培养学习习惯
• 职场人士：技能提升打卡，持续自我成长
• 健身爱好者：运动打卡，坚持锻炼计划
• 语言学习者：每日练习打卡，提高语言能力
• 阅读爱好者：阅读打卡，养成阅读习惯
• 自律人群：任何需要坚持的习惯养成

后续优化方向

1. 数据持久化：使用shared_preferences或sqflite保存数据
2. 云端同步：支持多设备数据同步
3. 社交功能：学习小组、好友互动、排行榜
4. 成就系统：解锁成就徽章，增加趣味性
5. 提醒功能：每日定时提醒打卡
6. 数据分析：更丰富的图表和统计分析
7. 学习笔记：记录每次学习的心得体会
8. 番茄钟：集成番茄工作法计时器
9. 数据导出：导出学习报告和数据
10. 主题定制：支持多种主题和配色方案

最佳实践

1. 代码组织：将大型Widget拆分为小组件，提高可维护性
2. 命名规范：使用清晰的变量和函数命名
3. 注释文档：为关键逻辑添加注释说明
4. 错误处理：添加适当的错误处理和用户提示
5. 性能优化：使用ListView.builder等优化列表性能
6. 用户体验：提供即时反馈和友好的错误提示
7. 测试覆盖：编写单元测试和Widget测试
8. 版本管理：使用Git进行版本控制

本项目提供了完整的学习打卡功能，代码结构清晰，易于理解和扩展。你可以在此基础上添加更多功能，打造一款功能丰富的学习助手应用。通过持续打卡，帮助用户养成良好的学习习惯，实现自我提升的目标。

重要提示：本应用使用模拟数据演示功能，实际使用需要集成数据持久化方案。建议使用shared_preferences存储简单数据，或使用sqflite存储复杂数据结构。
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