C++如何实现简单任务提醒程序

bool

#include <iostream> #include <vector> #include <string> #include <fstream> #include <sstream> #include <chrono> #include <iomanip> // For std::put_time  // 任务结构体 struct Task {     std::string description;     std::chrono::system_clock::time_point dueDate;     bool isCompleted;      // 辅助函数，将time_point转换为可读字符串     std::string getDueDateString() const {         std::time_t tt = std::chrono::system_clock::to_time_t(dueDate);         std::tm tm = *std::localtime(&tt);         std::ostringstream oss;         oss << std::put_time(&tm, "%Y-%m-%d %H:%M");         return oss.str();     } };  // 全局任务列表 std::vector<Task> tasks; const std::string DATA_FILE = "tasks.txt"; // 数据存储文件  // 加载任务 void loadTasks() {     std::ifstream file(DATA_FILE);     if (!file.is_open()) {         std::cerr << "Warning: Task data file not found or could not be opened. Starting with empty list.n";         return;     }      std::string line;     while (std::getline(file, line)) {         std::stringstream ss(line);         std::string desc;         std::string dateStr;         int completedInt;          // 简单的CSV-like解析: description,date,completed         std::getline(ss, desc, ',');         std::getline(ss, dateStr, ',');         ss >> completedInt;          Task t;         t.description = desc;         t.isCompleted = (completedInt == 1);          // 解析日期字符串为time_point         std::tm tm = {};         std::istringstream dateSs(dateStr);         dateSs >> std::get_time(&tm, "%Y-%m-%d %H:%M");         t.dueDate = std::chrono::system_clock::from_time_t(std::mktime(&tm));          tasks.push_back(t);     }     file.close();     std::cout << "Tasks loaded successfully.n"; }  // 保存任务 void saveTasks() {     std::ofstream file(DATA_FILE);     if (!file.is_open()) {         std::cerr << "Error: Could not open data file for saving!n";         return;     }      for (const auto& task : tasks) {         file << task.description << ","              << task.getDueDateString() << ","              << (task.isCompleted ? 1 : 0) << "n";     }     file.close();     std::cout << "Tasks saved successfully.n"; }  // 添加任务 void addTask() {     std::cout << "Enter task description: ";     std::string desc;     std::getline(std::cin >> std::ws, desc); // std::ws consumes leading whitespace      std::cout << "Enter due date and time (YYYY-MM-DD HH:MM): ";     std::string dateStr;     std::getline(std::cin, dateStr);      std::tm tm = {};     std::istringstream ss(dateStr);     ss >> std::get_time(&tm, "%Y-%m-%d %H:%M");      if (ss.fail()) {         std::cerr << "Invalid date/time format. Task not added.n";         return;     }      Task newTask;     newTask.description = desc;     newTask.dueDate = std::chrono::system_clock::from_time_t(std::mktime(&tm));     newTask.isCompleted = false;     tasks.push_back(newTask);     std::cout << "Task added.n";     saveTasks(); }  // 显示任务 void viewTasks() {     if (tasks.empty()) {         std::cout << "No tasks available.n";         return;     }     std::cout << "n--- Your Tasks ---n";     for (size_t i = 0; i < tasks.size(); ++i) {         std::cout << "[" << i + 1 << "] "                   << (tasks[i].isCompleted ? "[DONE] " : "")                   << tasks[i].description                   << " (Due: " << tasks[i].getDueDateString() << ")n";     }     std::cout << "------------------n"; }  // 标记任务完成 void completeTask() {     viewTasks(); // 先显示所有任务     if (tasks.empty()) return;      std::cout << "Enter the number of the task to mark as complete: ";     int taskNum;     std::cin >> taskNum;      if (taskNum > 0 && taskNum <= tasks.size()) {         tasks[taskNum - 1].isCompleted = true;         std::cout << "Task " << taskNum << " marked as complete.n";         saveTasks();     } else {         std::cerr << "Invalid task number.n";     } }  // 检查并提醒即将到期的任务 void checkReminders() {     std::cout << "n--- Upcoming/Overdue Reminders ---n";     bool found = false;     auto now = std::chrono::system_clock::now();      for (const auto& task : tasks) {         if (!task.isCompleted && task.dueDate <= now) {             std::cout << "[OVERDUE] " << task.description                        << " (Was due: " << task.getDueDateString() << ")n";             found = true;         } else if (!task.isCompleted && task.dueDate - now < std::chrono::hours(24)) { // 24小时内到期             std::cout << "[DUE SOON] " << task.description                        << " (Due: " << task.getDueDateString() << ")n";             found = true;         }     }     if (!found) {         std::cout << "No urgent reminders.n";     }     std::cout << "----------------------------------n"; }  // 主菜单和程序循环 void showMenu() {     std::cout << "nTask Reminder Programn";     std::cout << "1. Add Taskn";     std::cout << "2. View Tasksn";     std::cout << "3. Mark Task as Completen";     std::cout << "4. Check Remindersn";     std::cout << "5. Exitn";     std::cout << "Enter your choice: "; }  int main() {     loadTasks(); // 程序启动时加载任务      int choice;     do {         checkReminders(); // 每次显示菜单前检查提醒         showMenu();         std::cin >> choice;          switch (choice) {             case 1: addTask(); break;             case 2: viewTasks(); break;             case 3: completeTask(); break;             case 4: /* checkReminders() already called */ break;             case 5: std::cout << "Exiting program. goodbye!n"; break;             default: std::cerr << "Invalid choice. Please try again.n"; break;         }     } while (choice != 5);      // saveTasks(); // 退出前保存，在每个修改操作后保存更安全     return 0; }

tasks.txt

开会,2023-10-27 10:00,0

iomanip

nlohmann/json

loadTasks

time.h

ctime