从文件中读取数据到多个类对象

很高兴看到你为解决这个问题做出了努力。但是，您在问题中设置的内容与代码中的一些注释之间存在不匹配。在我看来，很明显，你的简报的一个关键部分是雇员对象本身需要能够将自己写入文件并从文件中读取自己。

您已经编写了将对象的内容写入文件的代码，而不是让对象将自己写入文件。这可能看起来像是我在吹毛求疵，但这是面向对象编程的本质。将功能封装在对象本身中才是真正的目标。

我在下面包含了一些代码来帮助你。希望这对你有帮助。

class employee
{
private:
    int _locEmpNumber;
    std::string _locName;
    std::string _locAddress;
    std::string _locPhone;
    double _locHrWorked;
    double _locHrWage;
public:
    employee();
    employee(int locEmpNumber, std::string locName, std::string locAddress, std::string locPhone, double locHrWorked, double locHrWage);
    //object should be able to save itself as per your project brief.
    void writeData(std::ofstream &empFile);
    //object should be able to read itself from file as per your project brief
    void readData(std::ifstream &empFile);
};
employee::employee()
{
    _locEmpNumber = 0;
    _locHrWorked = _locHrWage = 0;
}

employee::employee(int locEmpNumber, std::string locName, std::string locAddress, std::string locPhone, double locHrWorked, double locHrWage)
{
    _locEmpNumber = locEmpNumber;
    _locName = locName;
    _locAddress = locAddress;
    _locPhone = locPhone;
    _locHrWorked = locHrWorked;
    _locHrWage = locHrWage;
}
//
//From what I can glean from your brief ...
//Employee objects to write themselves out to the file!!!
void employee::writeData(std::ofstream &empFile)
{
    empFile << _locEmpNumber << std::endl;
    empFile << _locName << std::endl;
    empFile << _locAddress<< std::endl;
    empFile << _locPhone << std::endl;
    empFile << _locHrWorked << std::endl;
    empFile << _locHrWage << std::endl;
}
//
//Again, from what I can glean from your brief ...
//Have each object read itself in from the file!!!
void employee::readData(std::ifstream &empFile)
{
    //Normally you would have error handling in a method like this and
    //would either return a response that indicates that the operation
    //succeded or failed. You might alternatively use exception handling
    //or indeed a combination of both.
    //
    //Normally you would reset all members to initial / empty values before
    //reading values into them from your file. In this case we will omit that
    //for the purposes of simplicity. The main reason you would reset members
    //is to ensure that when reusing an object you don't end up with partial
    //data from the current "read" operation mixed with partial data that
    //was already in the object before you started reading.
    std::string inputStr;
    std::getline(empFile, inputStr);
    _locEmpNumber = atoi(inputStr.c_str());
    std::getline(empFile, _locName);
    std::getline(empFile, _locAddress);
    std::getline(empFile, _locPhone);
    std::getline(empFile, inputStr);
    _locHrWorked = atof(inputStr.c_str());
    std::getline(empFile, inputStr);
    _locHrWage = atof(inputStr.c_str());
}

int main(int argc, char* argv[])
{
    //Declarations
    const int ONE = 1;
    const int TWO = 2;
    int userInput;
    std::cout << "This program has two options:" << std::endl;
    std::cout << "1 - Create a data files called 'EmployeeInfo.txt', or" << std::endl;
    std::cout << "2 - Read data from a file and print paychecks." << std::endl;
    std::cout << "Please enter (1) to create a file or (2) to print checks: ";
    std::cin >> userInput;
    if (userInput == ONE)
    {
        //Create employee objects:
        employee joe(37, "Joe Brown", "123 Main St.", "123-6788", 45, 10.00);
        employee sam(21, "Sam Jones", "45 East State", "661-9000", 30, 12.00);
        employee mary(15, "Mary Smith", "12 High Street", "401-8900", 40, 15.00);
        std::ofstream empFile ("EmployeeInfo.txt");
        //Employee objects to write themselves out to the file.
        joe.writeData(empFile);
        sam.writeData(empFile);
        mary.writeData(empFile);
//      writeData(joe);
//      writeData(sam);
//      writeData(mary);
        //Close the file.
        empFile.close();
        //Print an message that creation of the file is complete.
        system("CLS");
        std::cout << "nCreation of 'EmployeeInfo.txt' has completed.n";
        std::cout << "nYou can now run option 2.n";
        //Exit.
        system("PAUSE");
        return 0;
    }
    else if (userInput == TWO)
    {
        //Create three new Employee objects, using the default Employee constructor.
        employee joe;
        employee sam;
        employee mary;
        //Open the file that you just saved.
        std::ifstream empFile("EmployeeInfo.txt");
        //Have each object read itself in from the file.
        joe.readData(empFile);
        sam.readData(empFile);
        mary.readData(empFile);
        empFile.close();
        //Call the printCheck( ) function for each of the three new objects, just as you did in the previous project.
        //I'll leave it to you to add this yourself.
    }
    else
    {
        system("CLS");      
        std::cout << "Incorrect entry.... Please try again and follow directions closely! n" << std::endl;
        system("PAUSE");
        return 0;
    }
    return 0;
}