How do I “Add Existing Item” an entire directory structure in Visual Studio?

Question

I have a free standing set of files not affiliated with any C# project at all that reside in a complicated nested directory structure.

I want to add them in that for

Answer 1

At last, Visual Studio 2017 allows the user to import an entire directory with a single click. Visual Studio 2017 has a new functionality "Open Folder" that allows opening the entire folder, even without the need to save it as solution. The source code can be imported using the following methods.

1. Menu File → Open → *Folder (Ctrl + Shift + O)
2. devenv.exe

It even supports building and debugging CMake projects.

Bring your C++ codebase to Visual Studio with “Open Folder”