Subj : Re: How to get address of CALLBACK function?
To   : borland.public.cpp.borlandcpp
From : Ed Mulroy [TeamB]
Date : Wed Mar 30 2005 06:55 am

In the code shown the function TWaveChannel::waveOutProc is a 
non-static class member function.

A callback function must either be a function not contained in a class 
or structure or a static member function of a class or structure.

..  Ed

> Gasparics, Antal wrote in message
> news:424a5dd6$1@newsgroups.borland.com...
>
> I need to define a callback function, and pass its address (as DWORD 
> type) to the WIN. Therefore, I need to identify the address of my 
> class memeber function, but I could not find the proper way for 
> that. Can anybody help me?
>
> This thing can not be compiled:
>
>    DWORD waveOutProcAddress;
>
>    waveOutProcAddress = &TWaveChannel::waveOutProc;
>
> I got this error message:
>
>    [C++ Error] Wave.cpp(26): E2034 Cannot convert 'void (__stdcall
>    TWaveChannel::*)(void *,unsigned int,unsigned long,unsigned
>    long,unsigned long)' to 'unsigned long'
>
> The definition of the functions is in this way:
>
> class TWaveChannel
> {
>  private:                     // Internal members
>    // Call back funtions
>    void CALLBACK waveOutProc(HWAVEOUT hwo,
>                              UINT uMsg,
>                              DWORD dwInstance,
>                              DWORD dwParam1,
>                              DWORD dwParam2);
> ....
> };

.