GDAL is a C++ translator library for more than 200 raster and vector geospatial data formats. It offers an API for a variety of languages such as C, C++, Python, Perl, C# and Java.
In the Visual Studio development environment it is possible to download NuGet packages. These are open source development libraries you can simply add to your .NET project.
A number of NuGet packages are available for GDAL. In addition to the complete GDAL environment, so-called .NET wrappers are installed with which C# functions in the underlying GDAL C++ DLLs can be called.
vdPConsulting is currently investigating the possibilities to implement GDAL/OGR functionality in a C# plugin in AutoCAD to export data to and import from GML, GeoJSON, GeoPackage and ESRI Shape files.