COM, C++/CLI, C# and CoInitialize()/CoUninitialize()

Question

Hi all,

I'm working on a project which makes use of COM in unmanaged C++. That unmanaged C++ is then wrapped in a managed C++ class. Finally, this managed C++ class is then consumed in a C# application. I'd like the unmanaged C++ and the wrapper to became a simple .NET dll

What is the best way to handle the call(s) to CoInitialize()/CoUninitialize() for the COM being used in the unmanaged C++?

I have the following options:
- Add a call to CoInitialize() in the constructor for the unmanaged C++ class and a call to CoUninitialize() in the destructor.
- Calling that functions each time a create a thread from C# trough a PInvoke call or trough a managed C++ wrapper.

I prefer the first method: do anyone see any issue with that?
Is there an easier way to do this?

Thanks

Answer 1

For threads created by the CLR, CoInitialize will be called already by the runtime. You only need to call it yourself if the C++ library creates any threads of its own.

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Mattias, C# MVP

Answer 2

Thanks.

But what is the best way to handle it in any alternate thread?!