Důkaz, že BuildUp u Unity funguje a provede method injection i při konfiguraci InjectionMethod v registraci, nejen přes atributy.

BuildUpInjectionMethod.cs

namespace UnityBuildUp
{
	public class IMyDependency
	{ }

	public class MyDependency : IMyDependency
	{ }

	public class MyService
	{
		[InjectionMethod]
		public void Init1(IMyDependency myDependency1)
		{
			MyDependency1 = myDependency1;
		}

		public void Init2(IMyDependency myDependency2)
		{
			MyDependency2 = myDependency2;
		}

		public IMyDependency MyDependency1 { get; set; }
		public IMyDependency MyDependency2 { get; set; }

	}

	class Program
	{
		static void Main(string[] args)
		{
			var container = new UnityContainer();
			container.RegisterType<IMyDependency, MyDependency>();
			container.RegisterType<MyService>(new InjectionMethod("Init2", typeof(IMyDependency))); // konfigurace má přednost před atributy, takže [InjectionMethod] se neuplatní
			//container.RegisterType<MyService>(); // takto (logicky) funguje pouze atribut

			var s1 = container.Resolve<MyService>();
			var s2 = new MyService();
			container.BuildUp(s2.GetType(), s2);

			Test(s1);
			Test(s2);
			
			Console.ReadLine();

		}

		static void Test(MyService service)
		{
			Console.WriteLine("MyDependency1 != null: {0}", service.MyDependency1 != null);
			Console.WriteLine("MyDependency2 != null: {0}", service.MyDependency2 != null);
		}
	}
}