.NET开发设计模式-单例模式

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Pattern.Singleton
{
    /// <summary>
    /// 单例模式1
    /// </summary>
    public class Singleton2
    {
        private static Singleton2 SingletonInstance;
        private static readonly object locker = new object();
        /// <summary>
        /// 定义私有构造函数,外界不能创建该实例
        /// </summary>
        private Singleton2()
        {

        }

        public static Singleton2 CreateSingleton()
        {
            if (SingletonInstance == null)
            {
                lock (locker)
                {
                    if (SingletonInstance == null)
                    {
                        return new Singleton2();
                    }
                }
            }
            return SingletonInstance;
        }
    }
}