So here is my current UnitOfWork implementation.  This one makes use of the somewhat new current_session_context_class feature. I think this is quite simple compared to some of the others you will find.

public interface IUnitOfWork : IDisposable    {        IUnitOfWork Start();        void BeginTransaction();        void CommitTransaction();        void RollbackTransaction(); }

public class UnitOfWork : IUnitOfWork    {        #region Dependencies        public ISessionFactory SessionFactory        {            get;            set;        }        #endregion #region IUnitOfWork Members public virtual void BeginTransaction() { var session = SessionFactory.GetCurrentSession(); if ( !session.Transaction.IsActive ) { session.BeginTransaction(); } } public virtual void CommitTransaction() { var session = SessionFactory.GetCurrentSession(); if ( session.Transaction.IsActive ) { session.Transaction.Commit(); } } public void RollbackTransaction() { var session = SessionFactory.GetCurrentSession(); if ( session.Transaction.IsActive ) { session.Transaction.Rollback(); } } public IUnitOfWork Start() { if ( !CurrentSessionContext.HasBind(SessionFactory) ) { var session = SessionFactory.OpenSession(); session.FlushMode = FlushMode.Commit; CurrentSessionContext.Bind(session); } return this; } #endregion #region IDisposable Members public void Dispose() { var session = CurrentSessionContext.Unbind(SessionFactory); var transaction = session.Transaction; if ( transaction.IsActive ) { transaction.Dispose(); } session.Dispose(); } #endregion }

 

All that’s required is this in the hibernate config section:

(for web apps):

    
     web
    

(for pretty much anything else): 

    
     thread_static
    

 

and just the barebones bootstrapping:

var sessionFactory = new Configuration().Configure().BuildSessionFactory();

Of course, to get this to work you need to register that sessionFactory instance into your IoC container, and register the UnitOfWork type with the container with a transient lifecycle.

 

From there you can either explicitly create and dispose IUnitOfWork instances for each operation, or set up a HttpModule to create one at the start of each request and dispose of it in the end_request event.