Help interoperability between C dll and vb.net

[babinton]

Hello Everyone,

I am new to interoperability between C dll and vb.net and I have been Having problems for quiet a while.

I have a dll file written in C that I got from an equipment manufacturer and I am trying to import and use it in vb.net, the dll functions I am having problems with are as follows:
1. Void GetNextCommand(Command *curCommand, LPVoid parameters, LPVoid ImageData)

2. void OCR_State(int nationCode, Byte *imageData, int imageSize, char *ocrString, int *ocrStringSize)

The following parameters are filled with values from the functions and returned to calling function.
for function 1 :parameters, imageData
for function 2 : *imageData, *ocrString
My main issue is that how do I marshall the parameters that should be returned to the calling function.

Regards