对Singleton Pattern的一点修改

重温经典

Singleton模式要求一个类有且仅有一个实例，并且提供了一个全局的访问点。

保证一个类仅有一个实例，并提供一个访问它的全局访问点！

简单实现

 1public sealed class Singleton
 2{
 3    static Singleton instance=null;
 4
 5    Singleton()
 6    {
 7    }
 8
 9    public static Singleton Instance
10    {
11        get
12        {
13            if (instance==null)
14            {
15                instance = new Singleton();
16            }
17            return instance;
18        }
19    }
20}

为了共享数据我对Singleton做了简单修改：

（在这里怎么做才能实现上面的折叠效果？）

 

namespace MyDream.Data
{
    public sealed class DataListInstance
    {
        public static volatile List<ThreeDGameInfo> _dataList = null;

        public static volatile List<ThreeDGameInfo> _halfDataList = null;

        public static readonly object obj = new object();

        public static void ReSetInstance()
        {
            _dataList = null;
            _halfDataList = null;
        }

        protected static void InitDataList()
        {
            string xmlFile = ConfigurationManager.AppSettings["XmlDataConfigPath"]+DreamConst.xmlDataSourceFile;

            _dataList = ThreeDGame.GetModeList(xmlFile) as List<ThreeDGameInfo>;//GetModelListFromXML(xmlFile);
           
        }

        public static void InitHalfDataList()
        {
            _halfDataList = ThreeDGame.GetHelfModelList(_dataList) as List<ThreeDGameInfo>;
        }

        public static List<ThreeDGameInfo> Instance()
        {
            if (_dataList == null)
            {
                lock (obj)
                {
                    if (_dataList == null)
                    {
                        InitDataList();
                    }

                }

            }

            return _dataList;
        }

        public static List<ThreeDGameInfo> HalfInstance()
        {
            if (_halfDataList == null)
            {
                lock (obj)
                {
                    if (_halfDataList == null)
                    {
                        InitHalfDataList();
                    }

                }

            }

            return _halfDataList;
        }

        public static List<ThreeDGameInfo> Get()
        {
            return Instance();
        }

        public static List<ThreeDGameInfo> GetHalf()
        {
            return HalfInstance();
        }

    }

}