Class Not Registered.... when trying to call a managed C# library from unmanaged C++

Question

Hey everyone,

I have a C# library that I am using for a COM object in unmanaged C++ code. I registered the library using Visual Studio's checkbox "Register For Com Interop" and set ComVisible to true.

imported the tlb to the C++ app..... when I run it, I get a "Class Not Registered"....

This has worked before, but this started happening after I moved the directory of my C# project to a different location.... yes I did re-register the library after I moved it.

I've removed all references from the registry... I 've even tried doing a gacutil.exe /i on it... no dice.

Anyone know how to fix this?

Answer 1

If you don't have explicit CLSID set on your managed object, it's possible that the move and rebuild has generated a new CLSID. Make sure your unmanaged project does not have a stale copy of the typelib.

Go to HKCR\CLSID\{XXXX} and ensure that the class registration for the managed object points to the right managed dll.

Answer 2

A better way of using unmanaged objects in managed code is to use C++ / CLI. You can easily create a managed wrapper around the native object.