学习使用NHibernate2.1.0Beta1（续七）— 单例模式

时间：2010-09-29 来源：Ferry

用类SingletonSession创建ISession对象

using System;
using NHibernate;
using System.Reflection;
using NHibernate.Cfg;

namespace CmsModels
{
    ///
    /// Sessions 的摘要说明。
    ///
    public class SingletonSession
    {
        private static readonly object lockObj = new object();
        private static ISessionFactory _factory;

        public SingletonSession()
        {
            //
            // TODO: 在此处添加构造函数逻辑
            //
        }
        public static ISessionFactory Factory
        {
            get
            {
                if (_factory == null)
                {
                    lock (lockObj)
                    {
                        if (_factory == null)
                        {
                            _factory = new Configuration().Configure().BuildSessionFactory();
                        }
                    }
                }
                return _factory;
            }
        }
        public static ISession GetSession()
        {
            return Factory.OpenSession();
        }
    }
}

数据访问对象示例：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NHibernate;
using NHibernate.Cfg;
using NHibernate.Criterion;

namespace CmsModels
{
    public class DAONews
    {
        public DAONews()
        {
        }
        /// <summary>
        /// Gets Menus by NID
        /// </summary>
        /// <param name="ID">News ID</param>
        /// <returns>IList<GTNews></returns>
        public IList<GTNews> GetNewsByNid(Int32 ID)
        {
            ICriteria cri = SingletonSession.GetSession().CreateCriteria(typeof(GTNews));
            cri.Add(Restrictions.Eq("NID", ID));
            cri.AddOrder(new NHibernate.Criterion.Order("NID", true));
            return cri.List<GTNews>();
        }

        public IList<GTNews> GetAllNews()
        {
            ICriteria cri = SingletonSession.GetSession().CreateCriteria(typeof(GTNews));
            cri.AddOrder(new NHibernate.Criterion.Order("IsTop",false));
            cri.AddOrder(new NHibernate.Criterion.Order("NID",false));
            return cri.List<GTNews>();
        }

        public bool Delete(String newIDs)
        {
            try
            {
                SingletonSession.GetSession().CreateSQLQuery("DELETE FROM GTNEWS WHERE NID IN (" + newIDs + ")").ExecuteUpdate();
                //注意在修改和删除时需要加下面一行代码
                SingletonSession.GetSession().Flush();
                return true;
            }
            catch
            {
                return false;
            }
        }

        public bool Save(GTNews news)
        {
            //try
            //{
                SingletonSession.GetSession().Save(news);
                return true;
            //}
            //catch
            //{
            //    return false;
            //}
        }

        public bool Update(GTNews news)
        {
            //try
            //{
            ISession _session = SingletonSession.GetSession();
            _session.Update(news);
            _session.Flush();
                return true;
            //}
            //catch
            //{
            //    return false;
            //}
        }

    }
}