TeenyIoc.cs

public class Args : Dictionary<string,object>{}

public class MyIoc
{
    private Dictionary<Type, Dictionary<string, Func<Args, object>>> _registry
        = new Dictionary<Type, Dictionary<string, Func<Args, object>>>();

    public void Register<T>(Func<Args, T> factory, string name = "") where T : class
    {
        Type t = typeof(T);
        if (!_registry.ContainsKey(t)) _registry[t] = new Dictionary<string, Func<Args, object>>();
        _registry[t][name] = factory;
    }


    public T Resolve<T>(string name)
    {
        return Resolve<T>(null, name);
    }

    public T Resolve<T>(Args args = null, string name = "")
    {
        args = args ?? new Args();
        Type t = typeof(T);
        if (!_registry.ContainsKey(t)) throw new InvalidOperationException();

        if (!_registry[t].ContainsKey(name)) throw new InvalidOperationException();

        var factory = _registry[t][name];
        return (T)factory.Invoke(args);
    }
}