Calling a C# dll from C++?

[dominicshaw]

Hi guys,

I am a C# developer (sorry) who has been thrown into some C++ (an Adobe toolbar). I basically want to open a window, get some input, and make a call to a WCF service. I can do this very easily and already have the code in a shared library in C#, so my preference is to simply make a call to a C# compiled DLL to show a form and let it do it's work...

From what I have read I can see this is possible and I have referenced the appropriate DLL, however I haven't got the foggiest how to call it.

I've tried namespace::class, namespace.class.method, using namespace namespace, and a myriad of other things but the namespace won't resolve.

How do you do this? Is it possible?

Alternatively I would be happy to write a form in the C++ environment, but when I add a form in Visual Studio it comes back with a load of "Object not set" errors and craps out.

Thanks in advance for any advice...

[guestgulkan]

I found this - It looks somewhat complicated.
http://support.microsoft.com/kb/828736

[webJose]

It is not as complex as it looks like. You are merely required to exposed the classes as COM coclasses so C++ can consume them. That's it The very good article found by guestgulkan just show how to do it step by step.

[Nexius]

When it comes down to it, a C# DLL still runs down to binary code just as a C++ DLL.

You're going to have to use the proper functions to load the dll and the function pointers.

http://msdn.microsoft.com/en-us/library/windows/desktop/ms684175%28v=vs.85%29.aspx

http://msdn.microsoft.com/en-us/library/windows/desktop/ms683212%28v=vs.85%29.aspx

[webJose]

Not sure what you mean, Nexius. A C# DLL doesn't export functions like regular C DLL's. The best way to interop with a managed DLL is through COM, like in the article posted by guestgulkan.

At least I have never seen anyone attempt something different.

[dominicshaw]

Hi all,

Thanks for all the responses. I've tried to implement it as described in the support article guestgulkan, but the project I have, the one from Adobe, won't compile with common language runtime support.

My reading agrees with webJose, in that I need a managed DLL. I have two problems with that - I don't really understand the difference between managed and unmanaged, and I suspect that the Adobe project won't compile as managed...? Without knowing what "managed" is, I don't know.

I successfully compiled and imported the C# library as a com visible dll, but could find no way to use it. The final parts of the article say to enable CLR support, but I can't do that, so that may be why.

I also had a look at pinvoke, but that method seems like it is reliant on the CLR too?

Out of my depth really, with the C++ bits, but I will take a look at LoadLibrary as described in Nexius's posts...

Any comments most welcome!