TSPLib.Net is a C# .Net wrapper library for TSPLIB (a library of sample instances for the TSP and related problems from various sources and of various types collected by Heidelberg university) that provides complete access to all the information provided in TSPLIB95 as of October the 2nd, 2020.
Install it from NuGet, or download from releases. The nuget package only contains the library. Nuget packages cannot copy contents to target projects. Thus, the TSPLIB95 directory must be copied to your solution directory manualy.
The TSPLIB95 directory contains data files and best known solutions information for the:
(the original descriptions of problems, used functions and file formats are available in the DOC.pdf file contained in this directory)
TspLib95 provides the entry point to TSPLIB95 instances and should be considered the default starting point for any application making use of TSPLib.Net. This class allows you to load instances by type, in total (entire library) or individually by name. It furthermore provides access to lists of instances by type, all instances in total, or individual instances by name (where name is the name of the file containing the specific problem instance excluding the file extension).
Each TSPLIB95 instance is wrapped within a TspLib95Item which ultimately provides all the available information for the specific TSP problem it wraps. In other words, not only is the TSP graph accessible (through IProblem and ProblemBase), but also the best known solutions (if they exist) in the form of optimal tours and optimal tour distances.
IntelliSense should take you the rest of the way, but please see the source if anything is lacking.
TSPLib.Net is distributed under the MIT license.