C++如何开发简单的订单管理系统

class

struct

class

private

public

Product

class Product {
private:
    std::string productId;
    std::string name;
    double price;

public:
    Product(std::string id, std::string n, double p)
        : productId(std::move(id)), name(std::move(n)), price(p) {}

    // Getter methods
    const std::string& getProductId() const { return productId; }
    const std::string& getName() const { return name; }
    double getPrice() const { return price; }

    // Setter methods (if needed, but for product, often immutable after creation)
    // void setPrice(double newPrice) { price = newPrice; }
};

productId

name

price

getter

std::string

OrderItem

Order

class OrderItem {
private:
    std::string productId; // 关联到具体商品
    std::string productName; // 方便显示，冗余但实用
    double unitPrice;
    int quantity;

public:
    OrderItem(std::string prodId, std::string prodName, double price, int qty)
        : productId(std::move(prodId)), productName(std::move(prodName)), unitPrice(price), quantity(qty) {}

    double getTotalItemPrice() const { return unitPrice * quantity; }
    // Getters...
};

// 定义订单状态的枚举类型，提高可读性和安全性
enum class OrderStatus {
    Pending,
    Confirmed,
    Shipped,
    Completed,
    Cancelled
};

class Order {
private:
    std::string orderId;
    std::string customerName;
    std::string customerContact;
    std::string orderDate; // 简单起见用字符串，实际可用日期时间类
    std::vector<OrderItem> items;
    double totalAmount;
    OrderStatus status;

public:
    Order(std::string id, std::string name, std::string contact, std::string date)
        : orderId(std::move(id)), customerName(std::move(name)), customerContact(std::move(contact)),
          orderDate(std::move(date)), totalAmount(0.0), status(OrderStatus::Pending) {}

    void addItem(const OrderItem& item) {
        items.push_back(item);
        totalAmount += item.getTotalItemPrice();
    }

    void updateStatus(OrderStatus newStatus) {
        status = newStatus;
    }

    // Getters for all members...
    const std::string& getOrderId() const { return orderId; }
    double getTotalAmount() const { return totalAmount; }
    OrderStatus getStatus() const { return status; }
    // ...以及获取订单项列表的方法
    const std::vector<OrderItem>& getItems() const { return items; }
};

Product

OrderItem

orders.txt

OrderManager

saveOrdersToFile(const std::string& filename)

#include <fstream>
#include <sstream> // 用于字符串构建

// 假设 OrderManager 内部有一个 std::vector<Order> allOrders;
void OrderManager::saveOrdersToFile(const std::string& filename) {
    std::ofstream outFile(filename);
    if (!outFile.is_open()) {
        std::cerr << "错误：无法打开文件 " << filename << " 进行写入。\n";
        return;
    }

    for (const auto& order : allOrders) {
        // 订单基本信息
        outFile << order.getOrderId() << ","
                << order.getCustomerName() << ","
                << order.getCustomerContact() << ","
                << order.getOrderDate() << ","
                << static_cast<int>(order.getStatus()) << "," // 枚举转整数保存
                << order.getTotalAmount();

        // 订单项信息，用 | 作为订单项之间的分隔符
        for (const auto& item : order.getItems()) {
            outFile << "|" << item.getProductId()
                    << ";" << item.getProductName()
                    << ";" << item.getUnitPrice()
                    << ";" << item.getQuantity();
        }
        outFile << "\n"; // 每个订单一行
    }
    outFile.close();
    std::cout << "订单数据已保存到 " << filename << "\n";
}

,

|

;

loadOrdersFromFile(const std::string& filename)

#include <fstream>
#include <sstream>
#include <vector> // 确保包含

// 辅助函数：将字符串分割成子字符串
std::vector<std::string> splitString(const std::string& s, char delimiter) {
    std::vector<std::string> tokens;
    std::string token;
    std::istringstream tokenStream(s);
    while (std::getline(tokenStream, token, delimiter)) {
        tokens.push_back(token);
    }
    return tokens;
}

void OrderManager::loadOrdersFromFile(const std::string& filename) {
    std::ifstream inFile(filename);
    if (!inFile.is_open()) {
        std::cerr << "错误：无法打开文件 " << filename << " 进行读取，可能文件不存在或无权限。\n";
        return;
    }

    allOrders.clear(); // 清空当前内存中的订单，加载新的
    std::string line;
    while (std::getline(inFile, line)) {
        if (line.empty()) continue; // 跳过空行

        std::vector<std::string> orderParts = splitString(line, '|'); // 先按订单项分隔
        if (orderParts.empty()) continue;

        // 解析订单基本信息
        std::vector<std::string> basicInfo = splitString(orderParts[0], ',');
        if (basicInfo.size() < 6) { // 至少有6个基本字段
            std::cerr << "警告：订单数据格式错误，跳过此行: " << line << "\n";
            continue;
        }

        std::string orderId = basicInfo[0];
        std::string customerName = basicInfo[1];
        std::string customerContact = basicInfo[2];
        std::string orderDate = basicInfo[3];
        OrderStatus status = static_cast<OrderStatus>(std::stoi(basicInfo[4]));
        double totalAmount = std::stod(basicInfo[5]);

        Order order(orderId, customerName, customerContact, orderDate);
        order.updateStatus(status); // 设置状态
        // 重新计算总金额，或者直接使用文件中的 totalAmount
        // 为了简化，这里我们直接使用文件中的 totalAmount，但在实际应用中，
        // 最好根据加载的订单项重新计算，以防止数据不一致。
        // order.totalAmount = totalAmount; // 假设Order类有setTotalAmount方法或可以直接修改

        // 解析订单项
        for (size_t i = 1; i < orderParts.size(); ++i) {
            std::vector<std::string> itemInfo = splitString(orderParts[i], ';');
            if (itemInfo.size() < 4) {
                std::cerr << "警告：订单项数据格式错误，跳过此项: " << orderParts[i] << "\n";
                continue;
            }
            std::string prodId = itemInfo[0];
            std::string prodName = itemInfo[1];
            double unitPrice = std::stod(itemInfo[2]);
            int quantity = std::stoi(itemInfo[3]);
            order.addItem(OrderItem(prodId, prodName, unitPrice, quantity));
        }
        allOrders.push_back(order);
    }
    inFile.close();
    std::cout << "订单数据已从 " << filename << " 加载。\n";
}