/// <summary>    /// Singleton泛型类    /// </summary>    /// <typeparam name="T"></typeparam>    public sealed class Singleton<T> where T : new()    {        private static T instance = new T();        private static object lockHelper = new object();        /// <summary>        /// 构造函数        /// </summary>        private Singleton()        { }        /// <summary>        /// 获取实例        /// </summary>        /// <param name="value"></param>        public static T GetInstance()        {            if (instance == null)            {                lock (lockHelper)                {                    if (instance == null)                    {                        instance = new T();                    }                }            }            return instance;        }          }