Use vcpkg to install protobuf libraries. Run commands from "Quick Start" section in vcpkg readme. Then install protobuf like so:
vcpkg install protobuf:x64-windows-static
vcpkg install protobuf:x86-windows-static
Either open the macro_record.sln file in VS2017 and press Build,
Or, in command-line, cd to the repository, and run (you'll need a NuGet CLI for this):
nuget restore
msbuild
The DLL is the C++ code which does the injecting and capturing of input. It exposes an API which is used by the GUI part, they communicate using protobuf.
Unit tests for the DLL.
C# WPF project, calls InjectAndCaptureDll for the actual work.
C++ console executable that's using the DLL.
The files common to the C++ and C# implementation, such as the protobuf definitions, protobuf-generated code, and the status codes enum.