查询会话返回null nHibernate

Question

这是我的sessionFactory类：

public static ISession OpenSession
        {
            get
            {
                try
                {
                    //   NHibernateProfiler.Initialize();
                    if (iSessionFactory == null)
                    {
                        lock (syncRoot)
                        {
                            if (iSessionFactory == null)
                            {
                                Configuration configuration = new Configuration().Configure("hibernate.cfg.xml");
                                Assembly assembly = Assembly.GetCallingAssembly();
                                configuration.AddAssembly(assembly);
                                iSessionFactory = configuration.BuildSessionFactory();
                                NHibernate.Context.CurrentSessionContext.Bind(iSessionFactory.OpenSession());
                                return iSessionFactory.OpenSession();
                            }
                        }
                    }
                    return GetCurrentSession();
                }
                catch (Exception ex)
                {
                    throw ex;
                }
            }
        }
        public static ISession GetCurrentSession()
        {
            try
            {
                return iSessionFactory.GetCurrentSession();
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }

这是我的实现类：

private  int stock_item_id = 0;
        public void testA()
        {
            //insert a stock item
            using (TransactionScope tx = new TransactionScope())
            {
                using (ISession session = SessionFactory.OpenSession)
                {
                    using (ITransaction transaction = session.BeginTransaction())
                    {
                        Stock stock = new Stock()
                        {
                            name = "chicken chouwmin"
                        };
                        session.Save(stock);
                        stock_item_id =Convert.ToInt32( stock.id);
                         var model = session.Get<Stock>(stock_item_id);
                    }
                }
                tx.Complete();
            }
          }

当我将调试器放入

时

  

var model = session.Get（stock_item_id）;   我得到一个非空模型

但是当我尝试使用CurrentSession在testB方法中使用相同的代码行删除相同的数据时，我得到null。这是我的第二堂课：

public void testB()
        {
            //delete a stock item
            using (TransactionScope tx = new TransactionScope())
            {
                using (ISession session = SessionFactory.OpenSession)
                {
                    using (ITransaction transaction = session.BeginTransaction())
                    {
                        var model = session.Get<Stock>(stock_item_id);
                        session.Delete(model);
                        transaction.Commit();
                    }
                }
                tx.Complete();
            }
        }

通过此方法调用以上两种方法：

public void testC()
        {
            //call function A and B
            using (TransactionScope tx = new TransactionScope())
            {
                testA();
                testB();
                tx.Complete();
            }
        }

背后的原因是什么？如何解决这个问题？