COM and .NET vs WinAPI

[kingting]

Thank you, I will take a look .

Now I just have to get interoperability working with my old C code...

I realize that both routes (WCF and COM) require significant rewrites in code. The question is, which would be more troublesome? I want to convince my employer that moving forward with a longterm .NET conversion and WCF is the way to go but in terms of implementation, what are the ups and downs and estimated development time?

1) From my understanding, code in both cases needs to be rewritten in some way (the source is just straight C compiled as an executable that utilizes several 3rd party dlls)
- For WCF, I would have to rewrite the functions that I need exported into a dll, then call them with p/Invoke to work with a CLR language and use the appropriate syntax to define the A,B,C's of WCF (using a Named Pipe Transport). The latter seems straightforward enough, I am mainly afraid of the rewriting of the original code
- For COM, how difficult would it be to restructure the code so the COM server runs as a standalone out of process .exe? Can I isolate the needed functionality and simply repackage those?
- For COM, would I have to expose global data structures using the IObjectData? Still hazy on this...

2) Why is COM obsolete?
- for example, we interface with programs like SolidWorks which utilize COM
- .NET and WCF provide many alternative modes of transport which are relatively easily implemented (e.g web interfacing)?

Sorry to keep bothering you Gurus! As I said, I know how to code, but don't really understand the architectures and technology behind it. I really appreciate the help from all of you. I've been fumbling around in the dark and it's all coming together slowly!