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我正在做作业，并且正在尝试遵循类图。在 Book.cpp 文件中，无论是注释文本，它都会导致错误提示：Unhandled exception at 0x00CE3F1B in Lab 1.exe: 0xC0000005: Access violation reading location 0xCCCCCD1C.

在下面的代码中，我不知道我应该用指针做什么，我不知道我应该如何将这个对象变量传递给这个构造函数或者我应该用它做什么。我对c++很困惑。我在这篇文章的末尾附上了类图。

Book::Book(string title, Author *pAuthor, Publisher *pPublisher, double price)
{
    setTitle(title);
    setPrice(price);
}

Book.cpp 文件：

#include <iostream>
#include <sstream>
using namespace std;

#include "Book.h"

Book::Book()
{
}

Book::Book(string title, Author *pAuthor, Publisher *pPublisher, double price)
{
    setTitle(title);
    setPrice(price);
}

void Book::setTitle(string  title)
{
    this->title = title;
}

void Book::setAuthorName(string first, string last)
{
    //pAuthor->setFirstName(first);
    //pAuthor->setLastName(last);
}

void Book::setPublisher(string name, string address, string city)
{
    //pPublisher->setName(name);
    //pPublisher->setAddress(address);
    //pPublisher->setCity(city);
}

void Book::setPrice(double price)
{
    this->price = price;
}

string Book::convertDoubleToString(double number)
{
    return static_cast<ostringstream*>( &(ostringstream() << number) ) -> str();
}

string Book::getBookInfo()
{
    return "0"; //title + "\n" + pAuthor->getFullName() + "\n" + pPublisher->getPublisherInfo() + "\n" + "$" + convertDoubleToString(price);
}

Book.h 文件

#include "Publisher.h"
#include "Author.h"

class Book
{
    public:
        Book();
        Book(string title, Author *pAuthor, Publisher *pPublisher, double price);
        ~Book();
        void setTitle(string title);
        void setAuthorName(string first, string last);
        void setPublisher(string name, string address, string city);
        void setPrice(double price);
        string convertDoubleToString(double number);
        string getBookInfo();

    private:
        string title;
        double price;
        Author *pAuthor;
        Publisher *pPublisher;
};

这就是我在 main.cpp 中的内容

#include <iostream>
#include <string>
using namespace std;

#include "Book.h"

int main()
{
    system("cls");

    cout << "Book 1" << endl;

    Author *pAuthor = new Author("John", "Doe");
    Publisher *pPublisher = new Publisher("Wrox", "10475 Crosspoint Blvd.", "Indianapolis");
    Book *pBook = new Book("Memory Management", pAuthor, pPublisher, 39.99);

    cout << pBook->getBookInfo() << endl;

    cout << endl << "Book 2" << endl;

    Book book;

    book.setTitle("Advanced C++ Programming");
    book.setAuthorName("Linda", "Smith");
    book.setPublisher("Microsoft Press", "One Microsoft Way", "Redmond");
    book.setPrice(49.99);

    cout << book.getBookInfo() << endl << endl;

    system("pause");

    return 0;
};

作者.cpp

#include <iostream>
#include <string>
using namespace std;

#include "Author.h"

Author::Author()
{
}

Author::Author(string first, string last)
{
    setFirstName(first);
    setLastName(last);
}

string Author::getFullName()
{
    return firstName + " " + lastName;
}

void Author::setFirstName(string first)
{
    this->firstName = first;
}

void Author::setLastName(string last)
{
    this->lastName = last;
}

发布者.cpp

#include <iostream>
#include <sstream>
#include <string>
using namespace std;

#include "Publisher.h"

Publisher::Publisher()
{
}

Publisher::Publisher(string name, string address, string city)
{
    setName(name);
    setAddress(address);
    setCity(city);
}

string Publisher::getPublisherInfo()
{
    return string(name + "\n" + address + "\n" + city);
}

void Publisher::setName(string name)
{
    this->name = name;
}

void Publisher::setAddress(string address)
{
    this->address =  address;
}

void Publisher::setCity(string city)
{
    this->city = city;
}

类图，因为我很迷茫。我相信我的结构是正确的，并且一些传递变量很好。但我只是不知道如何用指针来做。

在此处输入图像描述

4

1 回答 1

1

看起来您的类对象有两个指针，一个指向发布者，另一个指向作者，它们从未被初始化。当您尝试在这些对象上调用成员函数时，您会导致未定义的行为，特别是您的应用程序崩溃。

于 2012-09-04T00:48:17.820 回答