对Windsor使用Moq-Moq.Mock[IFoo]类型的对象不能转换为IFoo

_container.AddComponent("AutoBill", 
  typeof (AutoBillService), typeof (AutoBillService));

var mockUserRepository = new Mock<IUserRepository>();
var testUser = new User()
   {
     FirstName = "TestFirst",
     LastName = "TestLast", 
     UID=1
   };
mockUserRepository.Setup(repo => repo.GetUser(testUser.UID))
   .Returns(testUser);

_container.Kernel.AddComponentInstance("UserRepository", 
   typeof(IUserRepository), mockUserRepository);

var service = _container.Resolve<AutoBillService>(); //FAIL

这样做给了我一个例外:

有人能看出我做错了什么吗?