c# 设计模式-单例模式

来源：互联网发布：labview编程详解书编辑：程序博客网时间：2024/06/08 05:40

1、单线程简单实现

    public class SingletonObject    {        private static SingletonObject instance = null;        public static SingletonObject Instance        {            get            {                if (instance == null)                {                    instance = new SingletonObject();                }                return instance;            }        }        private SingletonObject()        {                    }    }

2、处理多线程

    public class SingletonObject    {        private static SingletonObject instance = null;        private static readonly object lockObj = new object();        public static SingletonObject Instance        {            get            {                lock(lockObj)                {                    if (instance == null)                    {                        instance = new SingletonObject();                    }                }                return instance;            }        }        private SingletonObject()        {                    }    }

3、双重检查加锁（double-checked locking）

    public class SingletonObject    {        private static SingletonObject instance = null;        private static readonly object lockObj = new object();        public static SingletonObject Instance        {            get            {                if(instance == null)                {                    lock (lockObj)                    {                        if (instance == null)                        {                            instance = new SingletonObject();                        }                    }                }                return instance;            }        }        private SingletonObject()        {                    }    }

4、静态初始化

（1）直接初始化方式

    public class SingletonObject    {        private static SingletonObject instance = new SingletonObject();        public static SingletonObject Instance        {            get            {                return instance;            }        }        private SingletonObject()        {                    }    }

（2）使用静态构造函数

    public class SingletonObject    {        private static SingletonObject instance = null;        public static SingletonObject Instance        {            get            {                return instance;            }        }        static SingletonObject()        {            instance = new SingletonObject();        }        private SingletonObject()        {                    }    }

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