VB using DLL error

[Guest_imported]

Hi there,

I have a VB program which makes use of DLL. And i encounter the error "Can't find DLL entry point". Does anyone know how to solve this problem.

Thanx

 

[jgdesignguru]

You need to know the structure of the DLL you are calling.
C++
If it is a C++ API DLL, then it will have either named entry points like SendMessage:

Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hWnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Long) As Long

Or numeric entry points, like the following hidden function in Shell32.DLL to shoe the find files dialog:

Declare Function SHFindFiles Lib "Shell32" Alias "#90" (ByVal pidlRoot As Long, ByVal pidlSavedSearchas As Long) As Boolean

You will need to find out the exact numeric entry point if named entry points do not exist.

ActiveX
If the DLL is an ActiveX DLL (built in VB?) then create a reference to it in the VB references menu. Then it class can be created as such:

'// Declare as follows
Dim objDLLClass As New myDLLClass

'// Call as follows
Call objDLLClass.myDLLFunction(myParam)

alternatively you can use the CreateObject method if no application refernce is required:

'// Declare as follows
Dim objDLLClass As Object
Set objDLLClass = CreateObject("myDLLname.myDLLClass")

'// Call as follows
Call objDLLClass.myDLLFunction(myParam)

Look in the MSDN for more details.

I hope this helps!