WindorContainerExtensions.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using Castle.MicroKernel;
using Castle.Windsor;

namespace Windsor.Extensions
{
    public static class WindorContainerExtensions
    {
        public static IEnumerable<T> GetInstancesFromBaseType<T>(this IWindsorContainer container, Assembly assembly)
        {
            var serviceTypes = GetDistinctServiceTypesFromImplementationTypes(container, GetReferencedTypes<T>(assembly));
            return serviceTypes.Select(type => (T) container.Resolve(type)).ToList();
        }

        private static IEnumerable<Type> GetDistinctServiceTypesFromImplementationTypes(IWindsorContainer container,
            IEnumerable<Type> implementationTypes)
        {
            var serviceTypes = new List<Type>();
            foreach (var handler in GetAllHandlers(container))
            {
                if (implementationTypes.Contains(handler.ComponentModel.Implementation))
                {
                    serviceTypes.AddRange(handler.ComponentModel.Services);
                }
            }
            return serviceTypes.Distinct();
        }

        private static IEnumerable<IHandler> GetAllHandlers(IWindsorContainer container)
        {
            return container.Kernel.GetAssignableHandlers(typeof(object));
        }

        private static IEnumerable<Type> GetReferencedTypes<T>(Assembly assembly)
        {
            return (
                from referencedAssembly in assembly.GetReferencedAssemblies()
                from type in Assembly.Load(referencedAssembly).GetTypes()
                where type.BaseType == (typeof(T))
                select type
            ).ToArray();
        }
    }
}