Can I run Visual Studio and .Net Framework in a docker container on Mac?

Visual Studio Code is a JavaScript application, which is what makes it nice a portable (and also kind of slow). The Visual Studio Framework is a different animal; one that is very territorial. Compiled applications that target the .NET framework will absolutely not run on MacOS, or Linux, or Solaris or..... anything not Windows. .NET core is portable to MacOS though.

As per this post (Can you install and run apps built on the .NET framework on a Mac?) there is the option of using Mono to recompile the code and run it on the Mac. Unfortunately, it does not support the full .NET Framework, and likely requires some non-trivial modifications to the code to make it work. If you go this route, you're either going to be limited to the areas of the Framework that are supported by Mono, or you'll have to maintain 2 different versions of the same code base. Neither option sounds very good to me.

As far as running in Docker, that will not work. Docker is fundamentally tied to the host operating system due to the use of kernel namespaces to provide isolation for processes and other system resources. It does not provide the same kernel API that the .NET Framework would require.

If you are absolutely determined to keep the development work on the Mac, the best option is probably to use a thick virtual machine that runs a full copy of Windows. This has the obvious downsides of being much more expensive (both in terms of the system resources it will need, and the software licensing costs), and you end up using Windows anyway (so you might as well just RDP to a real Windows machine). Probably not the answer you were hoping for (and I would love for someone to list some options that I've missed), but I think you're going to end up doing some work in Windows.