How to Access DLL Functions Using LoadLibrary and GetProcAddress?

Dynamically Loading Functions from DLLs

Question:

How can the LoadLibrary handle be used to access functions defined in a DLL?

LoadLibrary loads a DLL into memory but does not automatically import its functions. This requires a second WinAPI function: GetProcAddress.

Example:

#include <windows.h>
#include <iostream>

typedef int (__stdcall *f_funci)();

int main()
{
  HINSTANCE hGetProcIDDLL = LoadLibrary("C:\Documents and Settings\User\Desktop\test.dll");

  if (!hGetProcIDDLL) {
    std::cout << "could not load the dynamic library" << std::endl;
    return EXIT_FAILURE;
  }

  // Resolve function address using GetProcAddress
  f_funci funci = (f_funci) GetProcAddress(hGetProcIDDLL, "funci");
  if (!funci) {
    std::cout << "could not locate the function" << std::endl;
    return EXIT_FAILURE;
  }

  std::cout << "funci() returned " << funci() << std::endl;
  
  // Free the library handle when no longer needed
  FreeLibrary(hGetProcIDDLL);
  
  return EXIT_SUCCESS;
}

Dll Export:

Ensure the function is correctly exported from the DLL using the __declspec(dllexport) and __stdcall attributes:

int __declspec(dllexport) __stdcall funci() {
   // ...
}

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