I am not talking about .Net Core that runs on MacOS out-of-the-box. I am talking about .Net Framework 4.5 that only runs on Windows. This means that you need a Windows installation.
One option is to install Windows directly on Mac hardware, but this was never an option for me.
So the other option is to virtualize Windows. But this option implies 2 more concerns: which virtualization technology to use and which Windows version to virtualize.
Regarding virtualization I am using Oracle Virtual Box, it is free, works fine and I have been using it for years, so I didn’t even try other tool.
Regarding Windows, I tried different options and finally I decided to use what worked best for me: Windows 7 (64 bits) but with an “special setup”: no antivirus and updates turned off.
And finally, beyond Visual Studio and the usual stuff for .Net development I added the following software: