小技巧：NHibernate做完一个操作（事务级别）如何Callback?

 

 public interface ITransaction : IDisposable

    {

        bool IsActive { get; }

        bool WasCommitted { get; }

        bool WasRolledBack { get; }



        void Begin();

        void Begin(IsolationLevel isolationLevel);

        void Commit();

        void Enlist(IDbCommand command);

        void RegisterSynchronization(ISynchronization synchronization); //就是你了

        void Rollback();

    }

 

看到RegisterSynchronization(ISynchronization synchronization)这个方法了吗？这个方法就是给事务加入同步任务的。

 

public interface ISynchronization

    {

        void AfterCompletion(bool success);

        void BeforeCompletion();

    }

看到了吧？在完成之前，在完成之后，而且还带有一个事务是否成功。

 

于是，我们在Reposity里面注册这个，用2个Action即可实现完成后的Callback。

 

public virtual void MakePersistent(T entity, Action before, Action<bool> after)

        {

            Session.Transaction.RegisterSynchronization(new DefaultSynchronization(before, after));

            Session.SaveOrUpdate(entity);

        }

public class DefaultSynchronization : ISynchronization

    {

        private readonly Action _beforeCompletion;

        private readonly Action<bool> _afterCompletion;



        public DefaultSynchronization(Action<bool> after)

            : this(default(Action), after)

        { }



        public DefaultSynchronization(Action before, Action<bool> after)

        {

            _beforeCompletion = before;

            _afterCompletion = after;

        }



        public void AfterCompletion(bool success)

        {

            if (_afterCompletion != default(Action<bool>))

                _afterCompletion(success);

        }



        public void BeforeCompletion()

        {

            if (_beforeCompletion != default(Action))

                _beforeCompletion();

        }

如何使用？

这样：

MakePersistent(entity,()=>Console.Write("在事务之前执行”), isSuccess=>Console.Write(String.Format("在事务之后执行，结果:{0}", isSuccess)));