江湖救急~

Question

asp.net

Answer 1

加静态锁,最好用单例模式
        private static volatile pageCache instance = null;
        private static object thislock = new object();//静态锁
        private pageCache()
        {
            cache = SiteCache.GetCacheService();
            db = new DBTool();
        }
        /// <summary>
        /// 单体模式返回当前类的实例
        /// </summary>
        /// <returns></returns>
        public static pageCache GetCacheService()
        {
            if (instance == null)
            {
                lock (thislock)
                {
                    if (instance == null)
                    {
                        instance = new pageCache();
                    }
                }
            }
            return instance;
        }
        /// <summary>
        /// 添除商品信息
        /// </summary>
        public void clearCommodity()
        {
            lock (thislock)
            {
                cache.RemoveObject(_commodity_cache_path);
            }
        }
        /// <summary>
        /// 获取商品信息
        /// </summary>
        /// <returns></returns>
        public DataTable getCommodity()
        {
            DataTable _list = cache.RetrieveObject(_commodity_cache_path) as DataTable;
            if (_list == null)
            {
                lock (thislock)
                {
                    string query = "Select * From v_gl_indexCommodity ";
                    DataTable dt = db.ExecuteTable(query, null);
                    if (dt != null)
                    {
                        _list = dt;
                        cache.AddObject(_commodity_cache_path, _list);
                    }
                }
            }
            return _list;
        }