created 2006 · complexity basic · author John Cena · version 6.0
Here is how to fold the following region by typing
#region ... #endregion
Just add the following line in your cs.vim file placed in syntax folder beneath your vimruntime path.
let b:match_words = '\s*#\s*region.*$:\s*#\s*endregion'
It works even if the cursor is not on the "#region" keyword.