If you want to use VSCode with XSharp, you can already use the wonderful extension from Infominds that provides syntax highlighting for the X# programming language.
I've started to work on an extension that you can find in the download area : XSharp Tools for VSCode
It adds some context menus to build the current project, change some project settings, etc
Since V0.4.0 it also provides a basic syntax highlighting engine.
You can find the source at my GitHub page : xsharp-tools
