Keyed and generic services

Keyed services

container.Register<IStorage, BlobStorage>("blob");
container.Register<IStorage, DiskStorage>("disk");

var blob = container.Resolve<IStorage>("blob");

public sealed class Uploader([FromKeyedServices("blob")] IStorage storage);
public sealed class Named([ServiceKey] string key);   // receives the key it was resolved with

Registering with KeyedService.AnyKey provides a fallback for any key, following Microsoft’s semantics.

Open generics

container.Register(typeof(IRepository<>), typeof(Repository<>)).AsScoped();
var orders = container.Resolve<IRepository<Order>>();

A closed registration (IRepository<Order>) wins over the open one. Generic constraints are honored: an open generic that can’t close over a type is skipped.

Many implementations

Register replaces; RegisterEnumerable appends:

container.RegisterEnumerable<IValidator, NotEmptyValidator>();
container.RegisterEnumerable<IValidator, MaxLengthValidator>();

IReadOnlyList<IValidator> all = container.ResolveAll<IValidator>();   // registration order
public sealed class Form(IEnumerable<IValidator> validators);          // injected the same way

A single Resolve<IValidator>() returns the last registration.