Question

我正在写一个简单的程序来输入学生记录并将它们存储在昏迷分隔文件中。一切看起来都不错但是当我运行程序时出现错误：

错误1错误C2248：＆＃39; std :: basic_ios＆lt; _Elem，_Traits＆gt; :: basic_ios＆＃39; ：无法访问类中声明的私有成员＆＃39; std :: basic_ios＆lt; _Elem，_Traits＆gt;＆＃39; c：\ program files \ microsoft visual studio 10.0 \ vc \ include \ fstream 1116 1 project1

以下是代码：

#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是不可复制的，即使它们是，你也不想在这里这样做 - 而是通过引用传递。将您的newStudentRecord签名更改为：

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

话虽如此，当你不关心它们的初始值并且你不使用它们作为输出参数时，为什么要传递所有这些参数？将您的签名简化为以下内容：

void newStudentRecord(ofstream& writeToRecordsFile);

并将其他参数声明为newStudentRecord内的局部变量。

顺便说一句，在初始化之前，您正在阅读campusChoice，这将产生undefined behavior。

C ++中的fstream出错

1 个答案: