I was trying what was on this page, even though it says that the content is not updated regularly.
https://learn.microsoft.com/en-us/previous-versions/windows/desktop/legacy/ms692759(v=vs.85)
I created a C# class library, and pasted in the code at the bottom.
I think this first issue is this:
using Microsoft.ManagementConsole;
is not finding anything. And because of that, the classes that it is supposed to inherit from (SnapInInstaller and SnapIn) are not found.
When I try to find an assembly to reference, nothing is found.
I'm using Visual Studio 2019 because that's what works with Microsoft BizTalk Server 2020.
I also tried a really old sample from CodeProject, but it has C++ code in it, and my understanding is that now we should be able to create it all in C#. Any reference or link to any good documentation or example would greatly be appreciated.
I tried the Windows SDK based on this StackOverflow: mmc snap-ins extension I downloaded and installed: 22621.1778.230511-2102.ni_release_svc_prod3_WindowsSDK.iso
It installed the following selections to "D:\Windows Kit". It didn't put anything in Program Files\Microsoft SDKs\Windows\v6.1\Samples\SysMgmt\MMC3.0 as mentioned on the above link.
@NealWalters, based on my test, I also reproduced your problem that I could not find the MCC3 class library. I find that we need to download the sdk from here. However, I find the download link is useless. I recommend that you could submit the issue to recommend that Microsoft to fix the download link in their GitHub.
Thanks for your understanding and support.
Best Regards,
Jack