Bad DLL calling convention ???

[David Laplante]

I am trying to use the icq api but am getting this error message when I try to use one of the function.

The function set wich of MY functions (In my app) will be called when a certain notification from ICQ arrives...

here goes..
Now the documentation for the ICQ API is written for C++, I have managed to convert most of them but maybe this one is not converted correctly ?

What the documentation says:

void WINAPI ICQAPIUtil_SetUserNotificationFunc(UINT uNotificationCode, void *pUserFunc);

In a module:

Public Declare Function ICQSetUserNotificationFunc Lib "ICQMAPI.dll" Alias "ICQAPIUtil_SetUserNotificationFunc" (uNotificationCode As Integer, ByVal pUserFunc As Variant)

In the code of a form:

Call ICQSetUserNotificationFunc(1, AddressOf ICQOnlineListChange)

Is the function converted correctly ? if it is, what is the problem. If not , How should it be?

[Sam Finch]

Try

Public Declare Function ICQSetUserNotificationFunc Lib "ICQMAPI.dll" Alias "ICQAPIUtil_SetUserNotificationFunc" (uNotificationCode As Long, ByVal pUserFunc As Long)

[David Laplante]

Thanks for the reply...

I have tried your declaration but still get the same error message...

Any other ideas?

[David Laplante]

I just read about "_stdcall" for use with AdressOf...
Should I use this?
What is it?
How do I use it?

[ShepherdOfChaos]

Originally posted by David Laplante
I just read about "_stdcall" for use with AdressOf...
Should I use this?
What is it?
How do I use it?

In C++, you specify this as part of the function type
declaration to tell the compiler how the addressing is
handled. I've only had call to use this in a C++ DLL, so
don't know how it applies in VB.

[Edited by ShepherdOfChaos on 05-06-2000 at 12:08 AM]

[Sam Finch]

The 2nd is Definatley a function pointer, which means you need to declare it as a long and use the addressof operator

The First is a UINT which sounds like an unsigned integer but it could be a long one or a short one, so if the 2 longs don't work then try an integer and a long.


Actually I've just noticed it's a function so It returns something, which the C++ code doesn't try declaring it as a sub

[David Laplante]

YEAH BABY!

That worked! of course! how could I have not seen it... it was declared a VOID... wich means it doesn't return anything. It was a SUB not a FUNCTION

Thanks for your help!

[Sam Finch]

that's just one of those annoying things that nobody spots, I once spent 2 monts trying to debug a subclassing procedure only to realise that I'd forgotten to declare my parameters ByVal. D'OH

[Ceri]

Sometimes you can define a DLL function correct and then VB still tells you that it's not,

If you put an On Error Resume Next just before the DLL and an On Error Goto 0 just after the DLL, you will probably find that the function did execute allthough VB tell's you it didn't