title: .Net Standard (Not Core) Per Environment Configuration
body: <p>I am currently converting a .Net Framework class library to a .Net Standard class library.  In Framework we used app.config and had transform files to hold the environment specific data such as connection strings for the environment (Prod, Test, Dev).  </p>
  
  <p>I have scoured SO and Google for this answer but keep coming up empty.  What is the best way to store and retrieve this data in a .Net Standard class library?  At this point I don't care if I have a bit of code that populates properties based on my Build Settings or if I have a file sitting next to the DLL that houses this data.  I'm just needing a way to connect to ServerA in dev and ServerB in prod.</p>
  
  <p>I'll have either a .Net Core or .Net Framework project that references this DLL and asks this DLL for data but I want this library to house it's own DB connection, not passing it from the hundreds of apps calling it.</p>