C# interop - passing array of struct to a DLL.

[EDN Admin]

Hi all,

Ive been looking for some assistance on this all day with no luck, so any pointers would be helpful.

struct SID_SEARCH_RESULT_DATA
{
   ULONG ulFieldID;
   USHORT usFieldLength;
   char szFieldData[FIELD_LENGTH];
};

I want to pass this from a c# app into an unmanaged c++ dll and populate it. Ive tried a couple of things but with no joy - can anyone give me an idea of the c++ exported method signature and the c# extern method declaration required to pass an array of this struct and populate it?

The main complication is that I wont know how many results I will have up front, so I need to be able to assign sufficient memory on the c++ dll side.

Any help would be hugely appreciated.

Thanks , Lee.

Edit: The C++ dll is not a COM object or anything similar, just a straight DLL. Thats why I want to do this via p/invoke and some sort of marshalling wizardry. As you may be able to tell, this has landed on my desk with an urgent sticker on it and Im new to c# & .NET, so I just need to get it working.

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