Load dll function from other directory - c++

Question

in my new project, I got a problem about loading dll.
My file structure is like below:
D:\dll_directory\calculate.dll
D:\myproject\myproject.vcxproj
D:\running_place\myproject.exe
There're my code,
HMODULE h = LoadLibrary("D:\\dll_directory\\calculate.dll");
if(!h)
return GetLastError();
pfnInit = (PInit)GetProcAddress(h, "initialize");
if(!pfnInit())
{
// Fail
}
In my code of calculate.dll, I need to get the working directory so I use
int initialize() {
...
GetModuleFileName(...,myPath,...);
currentPath = ...; // get directory from path
filePath = currentPath + ...
if(!DoesExist(filePath))
return 0;
...
}
The problem is there. Because I loadlibrary dll from "D:\dll_directory\" in other directory, currentPath value is wrong.
In debugging, currentPath is "D:\myproject\debug..." and in executing, it's "D:\running_place\".
Only if place myproject.exe into the same place with calculate.dll, it shows correctly, currentPath = "D:\dll_directory\".
But I don't want to place dll manually because of many files and many places.
Additionally, I can not change code in dlls, it's stable.
Are there any ways to make it work?
Thanks in advance.
Updated: I modify my question to more clearer. Sr about this. It's my first time on stackoverflow.
In function Init of DLL, it need to run other files that are placed in the same place with it. The expected of currentPath is directory of DLL.
EXE in dir1 loads DLL in dir2, EXE calls function Init of DLL -> currentPath=dir1 (wrong).
Try to change DLL code with GetCurrentDirectory -> currentPath=dir1; still wrong.
Put EXE and DLL in dir2, EXE calls function Init of DLL -> currentPath=dir2 (expected).

Answer 1

You're indeed using the wrong function t get the current directory. GetCurrentDirectory returns the current directory (i.e. where .\thisFile.txt would be sought).
GetModuleFileName returns the name where the module came from. That's in general not the current working directory. That working directory can be pretty much anything, really. The variation you see between debug and release is just a small sample of the possible variation. Expect anything.
It also appears that you're looking for another file, other than the 3 mentioned in the question. It's unclear where that other file is located, so it's possible that this answer is incomplete. Is there a reason to expect that other file in the current working directory?

Answer 2

I find out these code that return the DLL current path.
EXTERN_C IMAGE_DOS_HEADER __ImageBase;
WCHAR DllPath[MAX_PATH] = {0};
GetModuleFileName((HINSTANCE)&__ImageBase, DllPath, _countof(DllPath));
Actually, I don't know what _ImageBase is and its cons/pros, am still investigating.
If ok, maybe I use it in DLL code.

Answer 3

The first argument of GetModuleFileName (which you left out) determines which path to get. From the observed behavior, we can now deduce that you passed NULL or 0, which means you get the filename of the EXE module.
You should have passed HMODULE h from your first snippet, the DLL module.
(This value is also available inside your DllMain, 1st argument. Save that 1st argument to a global variable in your DLL, so you can pass it to GetModuleFileName)