GetProcAddress() does not load the function from the dll - c++

Question

I need to import the dll function into my project and use it.
However, when importing it into my project with GetProcAddress() function it does not seem to work. Function returns null and the simple if check finishes the program.
I'm pretty sure there is some problem with my code, but I don't seem to be able to find it. Here is the code of Library.h file
#pragma once
#include <iostream>
#include <windows.h>
#include <string>
#include <cmath>
using namespace std;
#ifdef MY_DLL_EXPORTS
#define MY_DLL_API extern "C" _declspec(dllexport)
#else
#define MY_DLL_API extern "C" _declspec(dllimport)
#endif
struct args
{
int Elements;
int sum;
int* Array;
};
DWORD WINAPI NoSynchroSum(LPVOID);
void Monitoring(int);
Library.cpp file
#include "pch.h"
#include "framework.h"
#include "Library.h"
using namespace std;
DWORD WINAPI NoSynchroSum(LPVOID arg)
{
args* _args = (args*)arg;
for (int i = 0; i < _args->Elements; i++)
{
_args->sum += _args->Array[i];
}
return 0;
}
void Monitoring(int Elements)
{
int ElementsAmount = Elements;
HANDLE handle;
int suspendCount = 1;
int sum = 0;
srand(time(0));
int* Array = new int[ElementsAmount];
for (int i = 0; i < ElementsAmount; i++)
{
Array[i] = rand() % 21 - 10;
}
args* _args = new args;
_args->Elements = ElementsAmount;
_args->sum = sum;
_args->Array = Array;
handle = CreateThread(NULL, 0, NoSynchroSum, (LPVOID)_args, NULL, NULL);
cout << "Counted Sum = " << sum << endl;
CloseHandle(handle);
delete[] Array;
delete _args;
}
And my other project code, where i'm trying to import and use the function
#include <iostream>
#include <Windows.h>
using namespace std;
int main() {
HINSTANCE hInstance = LoadLibrary(L"D:\\Visual Studio 2022\\repos\\LabOS_7_DLL\\x64\\Debug\\DLLibrary.dll");
if (!hInstance) {
std::cout << "Library not loaded.\n";
return 1;
}
void (*pMainFunc)(int);
pMainFunc = (void(*)(int))GetProcAddress(hInstance, "Monitoring"); // експорт функції створення потоку
if (!pMainFunc)
{
std::cout << "Function not loaded.\n";
return 1;
}
int ElementsAmount = 0;
while (true)
{
cout << "enter size of array: ";
cin >> ElementsAmount;
if (ElementsAmount < 100)
{
cout << "size of array must be >=100\n";
continue;
}
break;
}
pMainFunc(ElementsAmount);
FreeLibrary(hInstance);
return 0;
}

Answer 1

I test the code and get the GetLastError:127 ERROR_PROC_NOT_FOUND:The specified procedure could not be found.
It means that there is no exported function with that name.
I suggest you should use the following code in the Library.h:
MY_DLL_API DWORD WINAPI NoSynchroSum(LPVOID);
MY_DLL_API void Monitoring(int);