单利模式

单例模式的核心:一是某个类只能有一个实例；二是它必须自行创建这个实例；三是它必须自行向整个系统提供这个实例。

写法过程:

1.创建一个静态变量用来生成实例

2.构造私有化

3.返回实例

using System;

namespace SingletonModel
{
    class Program
    {
        static void Main(string[] args)
        {
            EagerLogPrintPool.GetInstance().name="饥汉式单例模式";
            Console.WriteLine(EagerLogPrintPool.GetInstance().name);
            LasyLogPrintPool.GetInstance().name = "懒汉式单例模式";
            
            Console.WriteLine(LasyLogPrintPool.GetInstance().name);         
            Console.ReadKey();
        }
    }

    /// <summary>
    /// 饥汉式单例模式,一开始就实例化
    /// </summary>
    class EagerLogPrintPool
    {
        private static EagerLogPrintPool instance = new EagerLogPrintPool();
        public string name { get; set; }
        private EagerLogPrintPool()
        {

        }
        public static EagerLogPrintPool GetInstance()
        {
            return instance;
        }
    }
    /// <summary>
    /// 懒汉式单例模式,需要的时候才实例化
    /// </summary>
    class LasyLogPrintPool
    {
        private static LasyLogPrintPool instance;
        public string name { get; set; }
        private LasyLogPrintPool()
        {

        }
        public static LasyLogPrintPool GetInstance()
        {
            if (instance == null)
            {
                instance = new LasyLogPrintPool();
            }
            return instance;
        }

    }

}