C++书店管理系统程序

Question

我做了一个书店管理系统的C++程序，目前存在以下错误：
1、在VS code中调试程序，中文部分全部为乱码，更改cpp文件编码格式（UTF-8和ANSI）都没有用
2、保存图书信息时会覆盖掉过去的记录
3、图书信息查询时，不能正常查询
（包括：不能从读取的数据中获取信息，例如：我在data.txt中录入了图书A的信息，程序成功读取该文件，但不能查找到这本书；当此录入书籍后不能正常查询）
请帮我检查一下是哪里出了问题？

#include <iostream>
#include <fstream>
#include <vector>
#include <map>
#include <set>
#include <ctime>
#include <iomanip>
#include <windows.h>

using namespace std;

class Book {
public:
    string name;
    string author;
    string publisher;
    int pages;
    time_t latest_time;
    int stock;
    double price;

    Book(string n, string a, string p, int pg, int s, double pr) {
        name = n;
        author = a;
        publisher = p;
        pages = pg;
        latest_time = time(NULL);
        stock = s;
        price = pr;
    }

    friend ostream& operator<<(ostream& os, const Book& book) {
        os << "图书书名：" << book.name << endl;
        os << "图书作者：" << book.author << endl;
        os << "图书出版社：" << book.publisher << endl;
        os << "图书页数：" << book.pages << endl;
        os << "最新入库时间：" << put_time(localtime(&book.latest_time), "%Y-%m-%d %H:%M:%S") << endl;
        os << "图书库存量：" << book.stock << endl;
        os << "图书价格：" << book.price << endl;
        return os;
    }
};

class PurchaseRecord {
public:
    string name;
    string author;
    string publisher;
    int pages;
    time_t time1;
    int quantity;
    double price;

    PurchaseRecord(string n, string a, string p, int pg, int q, double pr) {
        name = n;
        author = a;
        publisher = p;
        pages = pg;
        time1 = time(NULL);
        quantity = q;
        price = pr;
    }

    friend ostream& operator<<(ostream& os, const PurchaseRecord& record) {
        os << "图书书名：" << record.name << endl;
        os << "图书作者：" << record.author << endl;
        os << "图书出版社：" << record.publisher << endl;
        os << "图书页数：" << record.pages << endl;
        os << "图书入库时间：" << put_time(localtime(&record.time1), "%Y-%m-%d %H:%M:%S") << endl;
        os << "图书进货数量：" << record.quantity << endl;
        os << "图书进货价格：" << record.price << endl;
        return os;
    }
};

class SalesRecord {
public:
    string name;
    string author;
    string publisher;
    int pages;
    time_t time2;
    int quantity;
    double price;

    SalesRecord (string n, string a, string p, int pg, int q, double pr) {
        name = n;
        author = a;
        publisher = p;
        pages = pg;
        time2 = time(NULL);
        quantity = q;
        price = pr;
    }

friend ostream& operator<<(ostream& os, const SalesRecord& record) {
    os << "图书书名：" << record.name << endl;
    os << "图书作者：" << record.author << endl;
    os << "图书出版社：" << record.publisher << endl;
    os << "图书页数：" << record.pages << endl;
    os << "图书销售时间：" << put_time(localtime(&record.time2), "%Y-%m-%d %H:%M:%S") << endl;
    os << "图书销售数量：" << record.quantity << endl;
    os << "图书销售价格：" << record.price << endl;
    return os;
}
};

class Bookstore
{
private:
vector<Book> books;
vector<PurchaseRecord> purchase_records;
vector<SalesRecord> sales_records;
set<string> warning_books;

public:
void add_book(string n, string a, string p, int pg, int s, double pr)
{
    Book book(n, a, p, pg, s, pr); books.push_back(book);
     }

void purchase(string n, string a, string p, int pg, int q, double pr) {
    PurchaseRecord record(n, a, p, pg, q, pr);
    purchase_records.push_back(record);

    for (auto& book : books) {
        if (book.name == n && book.author == a && book.publisher == p && book.pages == pg) {
            book.stock += q;
            book.latest_time = time(NULL);
            if (book.stock <= 1) {
                warning_books.insert(n);
            }
            return;
        }
    }

    add_book(n, a, p, pg, q, pr);
    warning_books.insert(n);
}

void sell(string n, string a, string p, int pg, int q, double pr) {
    SalesRecord record(n, a, p, pg, q, pr);
    sales_records.push_back(record);

    for (auto& book : books) {
        if (book.name == n && book.author == a && book.publisher == p && book.pages == pg) {
            book.stock -= q;
            book.latest_time = time(NULL);
            if (book.stock <= 1) {
                warning_books.insert(n);
            }
            return;
        }
    }
}
void query_book(string n, string a)
{
for (auto& book : books) {
if (book.name == n && book.author == a)
 {
cout << book << endl;
 return;
}
}

cout << "Error Message : Warning! The book information was not found! Please enter the correct book information!" << endl;
 }

void warning()
{
    if (warning_books.empty())
    {
        
        cout << "Message : There are currently no books that require warning!" << endl;
        return;
        }
        
        cout << "Message : The inventory of the following books is 1. Please purchase them in a timely manner:" << endl;
        for (auto& book : warning_books)
        {
            cout << book << endl;
            }
        }

void save_data()
{
    ofstream fout("data.txt");
    if (!fout)
    {
        
        cout << "Error Message : File opening failed!"<< endl;
        return;
        }

fout << "图书信息：" << endl;
for (auto& book : books) {
    fout << book << endl;
}

fout << "图书进货记录：" << endl;
for (auto& record : purchase_records) {
    fout << record << endl;
}

fout << "图书销售记录：" << endl;
for (auto& record : sales_records) {
    fout << record << endl;
}

fout.close();

cout << "Message : Data saved successfully!" << endl;
}

void load_data()
{
ifstream fin("data.txt");
if (!fin) {
    
    cout << "Error Message : File opening failed!" << endl;
return;
}

string line;
while (getline(fin, line)) {
    if (line == "图书信息：") {
        while (getline(fin, line) && line != "进货记录：") {
            string name, author, publisher;
            int pages, stock;
            double price;
            time_t latest_time;
            sscanf(line.c_str(), "书名：%s 作者：%s 出版社：%s 页数：%d 最新入库时间：%ld 库存量：%d 价格：%lf",
                &name, &author, &publisher, &pages, &latest_time, &stock, &price);
            Book book(name, author, publisher, pages, stock, price);
            book.latest_time = latest_time;
            books.push_back(book);
            if (stock == 1) {
                warning_books.insert(name);
            }
        }
    }
    else if (line == "进货记录：") {
        while (getline(fin, line) && line != "销售记录：") {
            string name, author, publisher;
            int pages, quantity;
            double price;
            time_t time;
            sscanf(line.c_str(), "书名：%s 作者：%s 出版社：%s 页数：%d 入库时间：%ld 进货数量：%d 进货价格：%lf",
                &name, &author, &publisher, &pages, &time, &quantity, &price);
            PurchaseRecord record(name, author, publisher, pages, quantity, price);
            record.time1 = time;
            purchase_records.push_back(record);
        }
    }
    else if (line == "销售记录：") {
        while (getline(fin, line)) {
            string name, author, publisher;
            int pages, quantity;
            double price;
            time_t time;
            sscanf(line.c_str(), "书名：%s 作者：%s 出版社：%s 页数：%d 销售时间：%ld 销售数量：%d 销售价格：%lf",
            &name, &author, &publisher, &pages, &time, &quantity, &price);
            SalesRecord record(name, author, publisher, pages, quantity, price);
            record.time2 = time;
            sales_records.push_back(record);
            }
            }
            }

fin.close();

cout << "Message : Data read successful!"<< endl;
}

void show_menu() {
    cout << "欢迎使用书店管理系统！" << endl;
    cout << "1. 添加图书" << endl;
    cout << "2. 进货入库" << endl;
    cout << "3. 销售出货" << endl;
    cout << "4. 查询图书信息" << endl;
    cout << "5. 自动预警提示" << endl;
    cout << "6. 保存数据到文件" << endl;
    cout << "7. 从文件中读取数据" << endl;
    cout << "0. 退出系统" << endl;
    cout << "请输入操作编号：";
    }

void run() {
    int choice;
    while (true) {
        show_menu();
        cin >> choice;
        switch (choice) {
            case 1: {
                string name, author, publisher;
                int pages, stock; double price;
                cout << "请输入书名："; cin >> name;
                cout << "请输入作者："; cin >> author;
                cout << "请输入出版社："; cin >> publisher;
                cout << "请输入页数："; cin >> pages;
                cout << "请输入库存量："; cin >> stock;
                cout << "请输入价格："; cin >> price;
                add_book(name, author, publisher, pages, stock, price);
                
                cout << "Message : Book added successfully!"<< endl;
                break;
                }
                case 2: {
                    string name, author, publisher;
                    int pages, quantity;
                    double price;
                    cout << "请输入书名：";
                    cin >> name;
                    cout << "请输入作者：";
                    cin >> author;
                    cout << "请输入出版社：";
                    cin >> publisher;
                    cout << "请输入页数：";
                    cin >> pages;
                    cout << "请输入进货数量：";
                    cin >> quantity;
                    cout << "请输入进货价格：";
                    cin >> price;
                    purchase(name, author, publisher, pages, quantity, price);
                    cout << "Message : Succeeded in purchasing and warehousing!" << endl;
                    break;
                    }
                    case 3: {
                        string name, author, publisher;
                        int pages, quantity;
                        double price;
                        cout << "请输入书名：";
                        cin >> name;
                        cout << "请输入作者：";
                        cin >> author;
                        cout << "请输入出版社：";
                        cin >> publisher;
                        cout << "请输入页数：";
                        cin >> pages;
                        cout << "请输入销售数量：";
                        cin >> quantity;
                        cout << "请输入销售价格：";
                        cin >> price;
                        sell(name, author, publisher, pages, quantity, price);
                        
                        cout << "Message : Sales shipment successful!" << endl;
                        break;
                        }
                    case 4: {
                        string name, author;
                        cout << "请输入书名：";
                        cin >> name;
                        cout << "请输入作者：";
                        cin >> author;
                        query_book(name, author);
                        break;
                        }
                    case 5: {
                        warning();
                        break;
                        }
                    case 6: {
                        save_data();
                        break;
                        }
                    case 7: {
                        load_data();
                        break;
                        }
                    case 0: {
                        cout << "感谢使用书店管理系统，再见！" << endl;
                        return;
                        }
                    default: {
                        
                        cout << "Error Message : Warning! No valid input information detected! Please re-enter!" << endl;
                        break;
                        }
                    }
                }
            }
};
int main()
{
    Bookstore bookstore;
    bookstore.run();
    return 0;
}

Answer 1

不知道你这个问题是否已经解决, 如果还没有解决的话:

• 以下回答来自chatgpt:

  可能出现了几个问题，需要逐一排查：

  1. 中文乱码：

  首先需要确保源代码文件的编码格式为UTF-8，并且在保存时选择“以UTF-8_WITH_BOM格式保存”（VS code中的设置可以通过Ctrl+Shift+P打开命令面板，搜索“文件编码”）。如果还是出现乱码，则需要在程序中添加代码以支持中文输出：

  #include <iostream>
  #include <locale>
  using namespace std;
  
  int main() {
      // 设置标准输出流的本地化类型为中文
      wcout.imbue(locale("chs"));
      // 输出中文
      wcout << L"你好，世界！" << endl;
      return 0;
  }
  

  上述代码中，wcout是一个输出流对象，通过调用它的imbue()方法来设置输出流的本地化类型为中文，然后就可以通过wcout输出支持中文的字符串了。

  1. 保存记录时覆盖以前记录：

  这个问题可能是由于每次保存时都是以覆盖写文件的方式实现的，而没有将新记录追加到文件的末尾。可以通过以下代码实现：

  #include <fstream>
  using namespace std;
  
  int main() {
      // 打开文件
      ofstream fout("data.txt", ios::app);
      // 写入数据
      fout << "book_A" << ',' << "author_A" << ',' << 100 << endl;
      // 关闭文件
      fout.close();
      return 0;
  }
  

  上述代码中，ofstream是一个输出文件流对象，通过设置打开方式为ios::app就可以实现追加写入文件。每次保存新记录时，就将新记录追加到文件末尾即可。

  1. 查询记录时出现问题：

  这个问题可能是由于查询条件不正确或数据格式不规范导致的。可以添加一些调试代码来查看程序的执行过程和变量值，以便快速定位问题。例如：

  #include <iostream>
  #include <fstream>
  #include <string>
  using namespace std;
  
  int main() {
      // 读取文件
      ifstream fin("data.txt");
      string line;
      while (getline(fin, line)) {
          // 调试代码
          cout << line << endl;
          // 解析数据
          // ...
      }
      // 关闭文件
      fin.close();
      return 0;
  }
  

  上述代码中，ifstream是一个输入文件流对象，通过getline()方法每次读取一行文件，并将该行文件输出到控制台以便调试。然后就可以查看输出结果，看看数据格式是否正确。如果数据格式不规范，可以添加一些代码来对数据进行格式化处理，以方便查询。

如果你已经解决了该问题, 非常希望你能够分享一下解决方案, 写成博客, 将相关链接放在评论区, 以帮助更多的人 ^-^