The code implements a localization in ASP.NET Core 3+ by non-compiled RESX file.

1. Download a content of folder src and include the files into your project (change namespace ...)

2. Initialization in Startup.cs in methode ConfigureServices

   services.AddOpenResxLocalization(options => options.ResourcesPath = "Resources");
   

3. Create a folder with name 'Resources' in base project folder and in it create folders by typical localization steps (You have to use a path naming - Globalization and localization in ASP.NET Core)
   For example:
   

4. Set properties of resx file

   • Build Action on Content
   • Copy to Output Directory on Copy always of on Copy if newer
     

5. It is all.

• It works with all type of localizations: in Controllers, in Views and in DataAnnotations.
• It is possible to use it in desktop applications, web applications (ASP.NET) and libraries.
• I don't have an expirience with hosting the code on Linux.

I have look for on the Internet libraries, nugets and articles on blogs where somebody solves this issue but I can not find anything. I have to create my own solution and I hope it helps you. If you have a tip for improvment, you will write it. I will pleasere.

• OpenResxResourceManager uses XDocument for finding a localized value, because I have found an article where somebody write. The XDocument is faster than XmlDocument. There is both impelementation (XDocument is used and XmlDocument is commented)
• OpenResxResourceManager has only one constructor but other constructors are commented.