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)));