Unity Container resolve a Dictionary of objects with same Interface

Question

I got the following block

 container.RegisterType<IService, ServiceA>("a");
 container.RegisterType<IService, ServiceB>("b");

I want to have a Dictionary of type Dictionary<string,IService>.

I will receive service name by parameter in an API rest and my idea is based on that parameter get the implementation I need from the Dictionary.

I can't figure out how to inject the Dictionary (with the resolved classes inside) into my business class. I want to do something like this.

private readonly IDictionary<string,IService> serviceDictionary;

public ClassConstructor (IDictionary<string,IService> dictionary)
{
    this.serviceDictionary = dictionary;
}

Answer 1

You should not inject IDictionary<string,IService> into your component, but instead an application-tailored abstraction:

public interface IServiceProvider
{
    IService GetService(string key);
}

This way you can create an implementation for Unity as follows:

public class UnityServiceProvider : IServiceProvider
{
    public IUnityContainer Container { get; set; }

    public IService GetService(string key) => Container.Resolve<IService>(key);
}

Now you can complete your registration as follows:

container.RegisterType<IService, ServiceA>("a");
container.RegisterType<IService, ServiceB>("b");
container.RegisterInstance<IService>(new UnityServiceProvider { Container = container });
container.RegisterType<ClassConstructor>();