23种设计模式之单例模式（Singleton）

 

单例模式确保某一个类只有一个实例，而且自行实例化并向整个系统提供这个实例，这个类称为单例类，它提供全局访问的方法。

 

public class SingleTon { private static SingleTon singleTon = null;//声明并初始化为null public SingleTon() { } /// <summary> /// 创建SingleTon对象 /// </summary> /// <returns></returns> public static SingleTon GetInstance() { if (singleTon == null) { singleTon = new SingleTon(); } return singleTon; } /// <summary> /// 调用测试方法 /// </summary> public void Print() { Console.WriteLine("打印吧"); } }

 

class Program { static void Main(string[] args) { //单例模式 SingleTon singleTon1 = SingleTon.GetInstance(); SingleTon singleTon2 = SingleTon.GetInstance(); SingleTon singleTon3 = SingleTon.GetInstance(); SingleTon singleTon4 = SingleTon.GetInstance(); SingleTon singleTon5 = SingleTon.GetInstance(); if (singleTon1 == singleTon2 && singleTon2 == singleTon3 && singleTon3 == singleTon4 && singleTon4 == singleTon5) { Console.WriteLine("相等"); singleTon1.Print(); } } }