How do you register/unregister an EXE as a COM object from C#?

Question

EDIT 5/11/2013: This question originally asked how to programmatically register a COM object using code from .NET without having to use REGASM. Yahia's answer covers both how to register a DLL programmatically and an EXE.

ORIGINAL QUESTION: At the moment, we have a batch script that we call from our UI to register/unregister our software in COM when setting the default version (using regasm and adding registry entries). We no longer wish to use a batch script as we are running into a problem where if the script fails, the program is not aware of the failure. There are several ways I can address the issue, but I don't like the notion of calling batch scripts from code if I don't have to, so I'd like to switch to registering our software with COM using managed code.

Assuming it's possible, how do you register/unregister COM objects from C#? Googling only turns up ways to do this from installer packages, or tells me to use regasm, but I can't find any information on how to do this programmatically or if it's even possible.

Thanks in advance for any assistance with this.

EDIT 5/10/2013: It looks like registering an EXE as a COM object is not the same as registering a DLL. Is there a programmatic way in .NET (PInvoke is fine) to register an EXE as a COM object (in the 32 bit registry)? This is currently how we're doing it in the script, the app and REGCMD vars are just shorthand:

    set app=%PathToTheExecutable%
    set REGCMD=%PathTo32BitRegExe%
    "C:\WINDOWS\Microsoft.NET\Framework\v4.0.30319\regasm" /tlb /codebase %app%
    %REGCMD% ADD HKCR\CLSID\{app-guid}\LocalServer32 /ve /t REG_SZ /d %app% /f
    %REGCMD% DELETE HKCR\CLSID\{app-guid}\InprocServer32 /f

Basically we run regasm on the executable, then add our exe as a LocalServer32 and remove the entry which associates us as an InprocServer. Is it possible to do this programmatically without having to call regasm from code?

Answer 1

You can do that in C# - but only by using some pinvoke, specifically LoadLibrary / GetProcAddress / FreeLibrary.

Basically you need to load the DLL, call the register/unregister functions inside that DLL and then unload it.

For a complete walkthrough including working C# source code see here. Reference see MSDN as per comment.

UPDATE after the OP updated the question:

The above method only works for DLLs.

With Assemblies (esp. EXE COM-server implemented in .NET) the easiest and most robust option is actually to use regasm.

IF you really need to do this programmatically you should take a look at these MSDN-links:

• http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.registrationservices.registerassembly%28v=vs.80%29.aspx

• http://msdn.microsoft.com/en-US/library/system.runtime.interopservices.registrationservices.registertypeforcomclients%28v=vs.80%29.aspx

Basically you need to load your EXE via Assembly.Load and then call RegisterTypeForComClients on the relevant Types.

Another option is to do this dynamically (at runtime) - perhaps this is of some use to you...