Launching a C# dialog from an unmanaged C++ mfc active x dll

Question

I've been told to write a dialog in C# which must be instantiated from an unmanaged c++ dll. We do this in other places in our code by simply adding a managed c++ class to the C++ project, then calling the C# dll from the managed c++ class. However I'm finding that doesn't work for me from where I have to do it. I think because the c++ dll is an MFCActiveX project. As soon as i set the clr on any file in this project, it will no longer register correctly. When i attempt to register it, i get three errors, then a message that it registered. However when i try to use it i get a 0x80040111 "ClassFactory cannot supply requested class" error. If anyone has any idea what the problem is here i would greatly appreciate it. I either need to be able to accomplish this (preferred) or prove that it's not possible.

Thanks

Answer 1

You must now register it with "regasm" instead of "regsvr32".

Answer 2

I can't see how a MFCActiveX project would prevent you from creating the C# class in this way. Unless it simply does not allow for a managed class to be added.

If you can't get the managed C++ class trick to work, another option is to use COM. It's possible to register a factory of sorts in the C# project as a COM object. Say give it the following interface

[ComVisible(true)]
[Guid("babe87fc-1467-4913-a1d3-47eeedf1afb5")]
public interface IDialogFactory {
  void Create(); 
}

You'd also have to create a backing class as well. But then you could register the managed assembly and use COM to access it.