C ++中的fstream错误

Question

I'm writing a simple program to enter student records and store them in a coma delimited file. Everything looks good but when I run the program I get an error:

Error 1 error C2248: 'std::basic_ios<_Elem,_Traits>::basic_ios' : cannot access private member declared in class 'std::basic_ios<_Elem,_Traits>' c:\\program files\\microsoft visual studio 10.0\\vc\\include\\fstream 1116 1 project1

Here's the code:

#include <cstring>
#include <iostream>
#include <fstream>
#include <string>
#include <cstdlib>

using namespace std;

void closeOrNewRecordMenu(string enterAnotherRecord)

    {
        if (enterAnotherRecord == "Q" && enterAnotherRecord == "q")
        {
        exit(0);
        }
    }

void newStudentRecord(double studentNumber, string firstName, string lastName, string campus, string course1, string course2, string course3, string seniorPracticum, ofstream writeToRecordsFile)

    {
        int campusChoice;
        do {
        cout << "Student's six digit number: (Numeric only)";
        cin >> studentNumber;
        cin.ignore();
        }
        while (studentNumber < 100000 && studentNumber > 999999);

        cout << "Student's first name: " << "\n";
        cin >> firstName;
        cin.ignore();

        cout << "Student's last name: " << "\n";
        cin >> lastName;
        cin.ignore();

        while (campusChoice < 1 || campusChoice > 3)

        cout << "Which campus will " << firstName << " " << lastName << " be attending class at: " << "\n";

        cout << "For the North campus enter 1" << "\n";

        cout << "For the South campus enter 2" << "\n";

        cout << "For the Seaside campus enter 3" << "\n";

        cin >> campusChoice;
        cin.ignore();

        if (campusChoice == 1)
            {
                campus = "North Campus";
        }

        else if (campusChoice == 2)
        {
            campus = "South Campus";
        }

        else if (campusChoice == 3)
        {
            campus = "Seaside Campus";
        }
        else {
            cout << "Please enter a valid choice." << "\n" << "\n";
        }

        cout << "Student's first course: " << "\n";
        getline (cin, course1);
        cin.ignore();

        cout << "Student's second course: " << "\n";
        getline (cin, course2);
        cin.ignore();

        cout << "Student's third course: " << "\n";
        getline (cin, course3);
        cin.ignore();

        do {
        cout << "Is " << firstName << " " << lastName << " a senior this year? Please enter \"Y\" for yes and \"N\" for no." << "\n";
        cin >> seniorPracticum;
        cin.ignore();
        } while (seniorPracticum != "y" && seniorPracticum != "Y" && seniorPracticum != "n" && seniorPracticum != "N");

        writeToRecordsFile << studentNumber << "," << firstName << "," << lastName << "," << campus << "," << course1 << "," << course2 << "," << course3 << "," << seniorPracticum << "\n";

        cout << "The student record for " << firstName << " " << lastName << " has been saved." << "\n" << "\n";
}

int main()

    {
         cout << "Hello there! Welcome to the student record manager. From here you can enter new student information and save it to a file!!!! (More exciting to the developer than the user)." << "\n" << "\n";

    string enterAnotherRecord;

    ofstream writeToRecordsFile;

    writeToRecordsFile.open("cop2224_proj1.txt");

        while (enterAnotherRecord != "Q" && enterAnotherRecord != "q") {
            cout << "Press \"N\" to create a new student record or press \"Q\" to quit." << "\n" << "\n";

            cin >> enterAnotherRecord;

            closeOrNewRecordMenu(enterAnotherRecord);

            string firstName, lastName, seniorPracticum, campus, course1, course2, course3;
            double studentNumber;

            newStudentRecord(studentNumber, firstName, lastName, campus, course1, course2, course3, seniorPracticum, writeToRecordsFile);   
        } 

    writeToRecordsFile.close();

    }

Answer 1

Streams are not copyable, and even if they were, you wouldn't want to do so here – pass by reference instead. Change your newStudentRecord signature to:

void newStudentRecord(double studentNumber, string firstName, string lastName, string campus, string course1, string course2, string course3, string seniorPracticum, ofstream& writeToRecordsFile);

That being said, why are you passing in all those arguments when you don't care about their initial values and you don't use them as output parameters? Simplify your signature to the following:

void newStudentRecord(ofstream& writeToRecordsFile);

and declare the other arguments as local variables inside of newStudentRecord .

---

As an aside, you're reading campusChoice before initializing it, which will yield undefined behavior .