How to merge managed and unmanaged dll into one dll

Question

How to merge managed and unmanaged dll into one dll? I want to merge two dlls in a single one. One is a c# managed dll, the other is a wrapped c++ managed dll with unmanaged c++ code. I have used ILMerge but it does not support unmanaged dll. And I have tested another commercial tool "Salamander .NET Linker", it does not support the unmanaged dll either. Someone even told me that it is not possible to merge managed and unmanged dll into one dll. Does anyboby know how to do this? Any advices are appreciated.

Mike G · Answer

Well it's been more than 10 years but people still trying to ilmerge unamanaged stuff into managed assemblies and that's normal. The nature of ilmerge is working with managed code. ilmerge never promised any support of usual dlls. Despite the questions like this one appear again and again on different forums nobody posts real answer (I don't think that extracting a managed dll from embedded resource into a temp directory is a real solution). The working solution can be implemented using virtualization - and it makes possible to support not only managed dlls but also unmanaged ones and any files at all. The tool called bxilmerge intercepts file calls and does everything as classic ilmerge but for any files. A link on github: https://github.com/boxedapp/bxilmerge/

ken du · Answer

Thanks for your quick and useful help. I have tried to wrap the unmanaged c++ code into managed and embed the wrapped c++ dll into the c# code as an embedded resource but MS2003 rejects to load the resource because it is a unmanaged resource. Any other suggestions? Thanks in advance.

Alan · Answer

Well it's technically possible to embed unmanaged code in a managed assembly because this is what the Managed C++ compiler does with 'mixed mode' code. However this technique is not nicknamed It just works for nothing and to my knowledge the precise mechanics of how it is done is not ducumented by Microsoft. Even if you could figure it out the CLR might refuse to run it if it sensed that the managed code was generated in part by the C# compiler. If you're trying to do this so that you can just package everything together then I'd have thought that a better approach would be to include the C++ mixed mode dll as a resource within the C# dll and then to include code in the latter (perhaps a static Initialize() method which the user has to call) to stream the dll to disk.