.NET Core and Swagger API generation

Solution: Use AddMvc() instead of AddMvcCore() in Startup.cs and it will work.

or write:

services.AddMvcCore().AddApiExplorer();

These links can help:

No service for type 'Microsoft.AspNetCore.Mvc.ViewFeatures.ITempDataDictionaryFactory' has been registered

https://github.com/domaindrivendev/Swashbuckle.AspNetCore/issues/299