嗨，我在调试后写了以下代码，当我尝试从（printdata（））函数返回的数据读取数据后读取文件内部时，我看到以下错误可以帮助我解决此错误吗？ 0x0F50DF58的未处理异常：0xC0000005：访问冲突读取位置0x0047CA04。
////////////Library.h
#include <string>
using namespace std;
class Library
{
private:
string BookName;
string Author;
int Day,Month,Year ; //day month year
float Price;
string Subject;
double ISBN;
public:
Library(string = "", string = "", int = 0, int = 0, int = 0, float = 0.0, string = "", double = 0.0);
void setBookName(string);
void setAuthor(string);
void setPurchaseDay(int );
void setPurchaseMonth(int);
void setPurchaseYear(int);
void setPrice(float);
void setSubject(string);
void setISBN(double);
string getBookName();
string getAuthor();
int getPurchaseDay();
int getPurchaseMonth();
int getPurchaseYear();
float getPrice();
string getSubject();
double getISBN();
};
///////Linrary.cpp
#include "stdafx.h"
#include "Library.h"
#include <iostream>
#include <string>
using namespace std;
Library::Library(string bookname, string author,int day,int month,int year, float price, string subject, double isbn)
{
setBookName(bookname);
setAuthor(author);
setPurchaseDay(day);
setPurchaseMonth(month);
setPurchaseYear(year);
setPrice(price);
setSubject(subject);
setISBN(isbn);
}
void Library::setBookName(string bookname)
{
BookName = bookname;
}
void Library::setAuthor(string author)
{
Author = author;
}
void Library::setPurchaseDay( int day)
{
Day = day;
}
void Library::setPurchaseMonth(int month)
{
Month = month;
}
void Library::setPurchaseYear(int year)
{
Year = year;
}
void Library::setPrice(float price)
{
Price = price;
}
void Library::setSubject(string subject)
{
Subject = subject;
}
void Library::setISBN(double isbn)
{
ISBN = isbn;
}
///////////////////////////////////////////////
string Library::getBookName()
{
return BookName;
}
string Library::getAuthor()
{
return Author;
}
int Library::getPurchaseDay()
{
return Day;
}
int Library::getPurchaseMonth()
{
return Month;
}
int Library::getPurchaseYear()
{
return Year;
}
float Library::getPrice()
{
return Price;
}
string Library::getSubject()
{
return Subject;
}
double Library::getISBN()
{
return ISBN;
}
////////main function
#include "stdafx.h"
#include "Library.h"
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>
#include <cstdlib>
using namespace std;
int menu();
void EnterData();
void PrintData();
int main(int argc, char *arg[])
{
for (;;)
{
system("cls");
int c = menu();
switch (c)
{
case 1:
EnterData();
break;
case 2:
PrintData();
break;
case 8:
exit(0);
}//end of switch
}//end of for
}
int menu()
{
int p;
do
{
cout << "1. Enter Data of a Book." << endl;
cout << "2. Print Data of all Books." << endl;
cout << "3. Search a Book by Subject." << endl;
cout << "4. Search a Book by Auther." << endl;
cout << "5. Pirnt Books Purchased in a Period of Time." << endl;
cout << "6. Search by ISBN." << endl;
cout << "7. Price of Books Purchased in a Period of Time." << endl;
cin >> p;
} while (p < 0 || p>7);
cin.get();
return p;
}//end of menu() function
//***************Enter Data to File****************8
void EnterData()
{
system("cls");
ofstream fp("LIB.txt", ios::out | ios::trunc);
if (!fp)
{
cerr << "\nError in opening file to write in...";
cin.get();
exit(1);
}
Library data1;
cout << "\nEnter data of the book and write '.' instead of name to finilize."<<endl<<endl;
string bookname, author, subject;
int day, month, year;
float price;
double isbn;
do{
cout << "\nBook Name: ";
getline(cin, bookname);
data1.setBookName(bookname);
if (bookname == ".")
{
author = ".";
subject = ".";
price = 0.0;
isbn = 0;
day = month = year = 0;
data1.setAuthor(author);
data1.setSubject(subject);
data1.setPrice(price);
data1.setISBN(isbn);
data1.setPurchaseDay(day);
data1.setPurchaseMonth(month);
data1.setPurchaseYear(year);
fp.write((char*)(&data1), sizeof(Library));
return;
}
cout << "\nAuthor: ";
getline(cin, author);
data1.setAuthor(author);
cout << "\nPurchase Date (day,month,year): ";
cin >> day;
cin >> month;
cin >> year;
cin.ignore();
data1.setPurchaseDay(day);
data1.setPurchaseMonth(month);
data1.setPurchaseYear(year);
cout << "\nPrice: ";
cin >> price;
data1.setPrice(price);
cin.ignore();
cout << "\nSubject: ";
getline(cin, subject);
data1.setSubject(subject);
cout << "\nISBN: ";
cin >> isbn;
data1.setISBN(isbn);
cin.ignore();
fp.write((char*)(&data1), sizeof(Library));
} while (1);
fp.close();
cin.get();
}//enter of enterdata() function
//***************Print Data********************
void PrintData()
{
system("cls");
ifstream fp("LIB.txt", ios::in);
if (!fp)
{
cerr << "\nError in opening file to write in...";
cin.get();
exit(2);
}
Library data2;
string bookname, author, subject;
int day, month, year;
float price;
double isbn;
cout << left << setw(12) << "BookName" << setw(12) << "Author" << setw(12) << "PurchaseDate"
<< right<<setw(7) << "Price" << setw(12) << "Subject" << setw(7) << "ISBN"<<endl;
cout << "____________________________________________________________________"<<endl;
fp.read((char *)(&data2), sizeof(Library));
while ( fp && !fp.eof())
{
bookname=data2.getBookName();
author=data2.getAuthor();
day=data2.getPurchaseDay();
month = data2.getPurchaseMonth();
year = data2.getPurchaseYear();
price = data2.getPrice();
isbn = data2.getISBN();
subject = data2.getSubject();
//cout << left << setw(12) << bookname << setw(12) << author << setw(12) << purchasedate[0] << purchasedate[1] << purchasedate[2]
//<< right << setw(7) << price << setw(12) << subject << setw(7) << isbn << endl;
if (bookname.at(0) == '.')
{
fp.close();
break;
}
fp.read((char *)(&data2), sizeof(Library));
}
cin.get();
//fp.close();
//return;
}
答案 0 :(得分：0)
免责声明我绝不是C程序员，这很可能是错误的。
您的问题可能来自这里：
fp.write((char*)(&data1), sizeof(Library));
您正在传递方法data1，但告诉它应该写入的文件的大小是Library的大小，而应该是数据的大小。
Library大于data1，将导致缓冲区溢出，您将尝试在其中读取应用程序/变量之外的内存地址。