title: .NET Core dependency injection -> Get all implementations of an interface
body: <p>I have a interface called IRule and multiple classes that implement this interface. I want to uses the .NET Core dependency injection Container to load all implementation of IRule, so all implemented rules.</p>
  
  <p>Unfortunately I can't make this work. I know I can inject an <code>IEnumerable&lt;IRule&gt;</code> into my ctor of the controller, but I don't know how to register this setup in the Startup.cs</p>