public class StaticCacheTest    {        private static IDictionary<string, object> _dic;         private static object locker = new object();                 private static IDictionary<string, object> CachedDic        {            get            {                if (_dic == null)                {                    lock (locker)                    {                        if (_dic == null)                        {                            _dic = new Dictionary<string, object>();                        }                    }                }                return _dic;            }        }        public static object GetObject(string key)        {            return CachedDic[key];        }        public static void SetObject(string key, object obj)        {            lock (locker)            {                CachedDic[key] = obj;            }        }    }    public partial class _Default : System.Web.UI.Page    {        private const string KEY = "CurrentTime";        protected void Page_Load(object sender, EventArgs e)        {            String curTime = System.DateTime.Now.ToString();            if (HttpContext.Current.Application[KEY] == null)            {                HttpContext.Current.Application.Lock();                HttpContext.Current.Application[KEY] = curTime;                HttpContext.Current.Application.UnLock();            }            if (HttpContext.Current.Cache[KEY] == null)            {                HttpContext.Current.Cache.Insert(KEY, curTime);            }            if (StaticCacheTest.GetObject(KEY) == null)   //本质上就是HttpRuntime.Cache的实现方式            {                StaticCacheTest.SetObject(KEY, curTime);            }            if (HttpRuntime.Cache[KEY] == null)            {                HttpRuntime.Cache.Insert(KEY, curTime);   //HttpRuntime.Cache与HttpContext.Current.Cache是同一对象,建议使用HttpRuntime.Cache                            }            TextBox1.Text = HttpContext.Current.Application[KEY].ToString();            TextBox2.Text=HttpContext.Current.Cache[KEY].ToString();            TextBox3.Text=StaticCacheTest.GetObject(KEY).ToString();        }    }