understanding header files for dll import wizard

[southmalaitaboy]

I'm trying to use the import dll wizard to import some external code for a camera that I purchased. Labview is having some trouble interpreting the header file for the library so I'm trying to work my way through the header file to understand it. One line of code that seems to be contributing to my problems is;

typedef void (LINKCONVENTION FGCALLBACK)(void* Context,UINT32 wParam,void* lParam);

I'm fairly new to using C++ so I'm not entirely sure what this line of code is doing. Is there anyone out there that could help explain to me what this code is doing?

Thanks in advance,

Philip Ashley

[Jacemdom]

I'm trying to use the import dll wizard to import some external code for a camera that I purchased. Labview is having some trouble interpreting the header file for the library so I'm trying to work my way through the header file to understand it. One line of code that seems to be contributing to my problems is;

typedef void (LINKCONVENTION FGCALLBACK)(void* Context,UINT32 wParam,void* lParam);

I'm fairly new to using C++ so I'm not entirely sure what this line of code is doing. Is there anyone out there that could help explain to me what this code is doing?

Thanks in advance,

Philip Ashley

Maybe some help at :

http://forums.lavag.org/index.php?showtopi...p;hl=dll+import

http://forums.lavag.org/index.php?showtopi...p;hl=dll+import

[Rolf Kalbermatter]

I'm trying to use the import dll wizard to import some external code for a camera that I purchased. Labview is having some trouble interpreting the header file for the library so I'm trying to work my way through the header file to understand it. One line of code that seems to be contributing to my problems is;

typedef void (LINKCONVENTION FGCALLBACK)(void* Context,UINT32 wParam,void* lParam);

I'm fairly new to using C++ so I'm not entirely sure what this line of code is doing. Is there anyone out there that could help explain to me what this code is doing?

This is not C++ and the DLL importer couldn't deal with C++ at all. It's standard C and defines a function pointer that can be used as callback parameter to another function. As such it is an advanced C feature a lot of people have trouble to understand.

Worse it is not something LabVIEW could do directly for you, so if you need to use the function that takes this function pointer as a parameter, you can't do without writing an intermediate DLL and converting in there the callback into an occurrence or user event for LabVIEW.

Rolf Kalbermatter