[SOLVED] VB6: Get current path of a DLL

VB6: Get current path of a DLL

I need to determine the path of the current dll / ocx at runtime on VB6. Can't use app.path because it returns the path of the exe that's using the dll.

Solution

Based on this answer getThisDLLPath() returns the fully qualified name of the current dll/ocx

GetModuleHandleExA gets the handle of a public function in a loaded dll.

GetModuleFileNameW gets the fullpath of a handle

getThisDLLPath() is also used as a target memory address for GetModuleHandleExA, so it needs to be public and on a bas file.

Option Explicit
Private Declare Function GetModuleFileNameW Lib "kernel32.dll" _
    (ByVal hModule As Long, ByVal lpFilename As Long, ByVal nSize As Long) As Long
Private Declare Function GetModuleHandleExA Lib "kernel32.dll" _
    (ByVal dwFlags As Long, ByVal lpModuleName As Long, ByRef phModule As Long) As Boolean

Private Const GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS As Long = &H4
Private Const GET_MODULE_HANDLE_EX_FLAG_PIN As Long = &H1
Private Const GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT As Long = &H2

Private Function getThisDLLHandle() As Long
    Call GetModuleHandleExA(GET_MODULE_HANDLE_EX_FLAG_FROM_ADDRESS Or _
             GET_MODULE_HANDLE_EX_FLAG_UNCHANGED_REFCOUNT, _ 
             AddressOf getThisDLLPath, getThisDLLHandle)
End Function

Public Function getThisDLLPath() As String
    Const MAX_PATH = 260&   
    Dim lphandle As Long        
    lphandle = getThisDLLHandle

    GetThisDLLPath = Space$(MAX_PATH - 1&)
    Call GetModuleFileNameW(lphandle, StrPtr(GetThisDLLPath), MAX_PATH)
End Function