Im maintaining a legacy app in VC6 aka VS6 (release date 1998, wikipedia), don't have time to upgrade it now. I have found a previous bug in this version I think I found another.
I'm trying to write objects to disk and read them back. This code works in a counsel app WITHOUT MFC. I can't get it to work in an MFC SDI FORVIEW app.
I created an SDI FORMVIEW APP and place a Listbox and Button on the screen. I placed the following code in the button message handler. This is just a test App to test the code.
Note the list function takes a pointer to the listbox so as you all know you have to create a control variable in classwizard to the listbox
In a counsel app I can add and read objects fine, but in the MFC version all I get is junk in the list box and message box.
Can you guys try it in a newer Visual Studio? Or am I overlooking something? I don't use std::string much as I'm more of a CString guy, but I'm very interested in writing/reading std::cstring obects to file since I haven't found a way to write CString objects to file and accesses the files in random access mode.
Thanks in advance.
I have version 2003 profesional but haven't installed it. If some one has it please try it on that verision. It's a big project and porting it might cause issues.
I'm trying to write objects to disk and read them back. This code works in a counsel app WITHOUT MFC. I can't get it to work in an MFC SDI FORVIEW app.
I created an SDI FORMVIEW APP and place a Listbox and Button on the screen. I placed the following code in the button message handler. This is just a test App to test the code.
Note the list function takes a pointer to the listbox so as you all know you have to create a control variable in classwizard to the listbox
In a counsel app I can add and read objects fine, but in the MFC version all I get is junk in the list box and message box.
Can you guys try it in a newer Visual Studio? Or am I overlooking something? I don't use std::string much as I'm more of a CString guy, but I'm very interested in writing/reading std::cstring obects to file since I haven't found a way to write CString objects to file and accesses the files in random access mode.
Thanks in advance.
I have version 2003 profesional but haven't installed it. If some one has it please try it on that verision. It's a big project and porting it might cause issues.
Code:
//top of file
#include "stdafx.h"
//......
#include <string>
#include <iostream>
#include <fstream>
using namespace std;
void MYFORMVIEW::OnButtonDbCpp()
{
class Person{
public:
std::string m_Name;
int m_Age;
int m_Ratings;
void InitPerson( std::string Name, int Age, int Ratings){
m_Name = Name;
m_Age = Age;
m_Ratings = Ratings;
};
};
class Person_IO{
public:
void WritePerson( Person P, std::string Name, int Age, int Ratings){
P.m_Name = Name;
P.m_Age = Age;
P.m_Ratings = Ratings;
ofstream outfile;
outfile.open("persfile.dat", ios::app | ios::binary);
//file.read((char*)&obj, sizeof(obj)); //doesn't work either
outfile.write(reinterpret_cast<char*>(&P),sizeof(P));
outfile.flush();
outfile.close();
}
void ReadAllPersons( Person P, CListBox* pList){
//P.m_Name = Name;
//P.m_Age = Age;
//P.m_Ratings = Ratings;
ifstream infile;
infile.open("persfile.dat", ios::binary);
while(1){
//file.read((char*)&obj, sizeof(obj)); //doesn't work either
infile.read(reinterpret_cast<char*>(&P),sizeof(P));
if(infile.eof()) break;
pList->AddString(P.m_Name.c_str());
::AfxMessageBox(P.m_Name.c_str());
};
infile.close();
}
};
Person Per;
Person_IO P_IO;
P_IO.WritePerson( Per, "Joe Baker",42, 125);
P_IO.WritePerson( Per, "Sam Valet",52, 12);
P_IO.WritePerson( Per, "Don Tracy",55, 912);
P_IO.ReadAllPersons( Per, &m_CList1);
}
