記錄學習過程

單例模式:單例模式就是保證一個類,只有一個實例;

    class Singleton
    {
        private static Singleton _instance = null;
        private static readonly object SynObject = new object();

        // 定義私有構造函數，使外界不能創建該類實例
        private Singleton()
        {
        }

        public static Singleton Instance
        {
            
 
get
            {
                if (_instance == null)
                {
                    lock (SynObject)
                    {
                        if (_instance == null)
                        {
                            _instance = new Singleton();
                        }
                    }
                }

                
 
return _instance;
            }
        }
    }

設計模式一(單例模式)