Can we also use simple injector with unity pattern?

Irem,

Thanks for your question. I started with showing registering concrete types with the Simple Injector DI container in order to keep the examples as simple as possible. All of the popular .NET DI containers, including Simple Injector, support registering concrete types or registering interface/concrete type mappings.

The main benefit of registering interfaces with the DI container is that dependent classes (like our controller in the ASP.NET Core example) only take a dependency on the interface and not on a specific concrete type. This further improves the loose coupling between classes. And it allows you to easily replace the concrete type that the container will instantiate for that interface by changing the concrete type in your container configuration that's associated with that interface.

Thanks ~James