单例模式演示-1-39-07

  1 using System;
  2 using System.Collections.Generic;
  3 using System.Linq;
  4 using System.Text;
  5 using System.Threading;
  6 
  7 namespace _01单例模式演示
  8 {
  9     class Program
 10     {
 11         static void Main(string[] args)
 12         {
 13 
 14             //for (int i = 0; i < 100; i++)
 15             //{
 16             //    Person p = new Person();
 17 
 18             //    Person p1 = new Person();
 19             //}
 20 
 21             //Person p = new Person(
 22 
 23             //for (int i = 0; i < 1000; i++)
 24             //{
 25             //    Person p = Person.GetInstance();
 26             //}
 27 
 28             for (int i = 0; i < 1000; i++)
 29             {
 30 
 31                 Thread t = new Thread(new ThreadStart(() =>
 32                 {
 33                     //Person p = Person.GetInstance();
 34                     //Singleton p = Singleton.GetInstance();
 35 
 36                     Singleton2 s2 = Singleton2.GetInstance();
 37                 }));
 38                 t.Start();
 39             }
 40             Console.WriteLine("ok");
 41             Console.Read();
 42 
 43 
 44 
 45 
 46 
 47         }
 48     }
 49 
 50 
 51     //利用静态字段，在第一次使用类的时候只初始化一次的特性。
 52     public class Singleton2
 53     {
 54         private Singleton2()
 55         {
 56             Console.WriteLine(".");
 57         }
 58         private static readonly Singleton2 _instance = new Singleton2();
 59 
 60         public static Singleton2 GetInstance()
 61         {
 62             return _instance;
 63         }
 64     }
 65 
 66 
 67 
 68 
 69 
 70 
 71 
 72     public class Singleton
 73     {
 74         private Singleton()
 75         {
 76             Console.WriteLine(".");
 77         }
 78 
 79         private static Singleton _instance;
 80 
 81         private static readonly object syn = new object();
 82 
 83         public static Singleton GetInstance()
 84         {
 85             //lock (syn)
 86             //{
 87             //    if (_instance == null)
 88             //    {
 89             //        _instance = new Singleton();
 90             //    }
 91             //    return _instance;
 92             //}
 93             if (_instance == null)
 94             {
 95                 lock (syn)
 96                 {
 97                     if (_instance == null)
 98                     {
 99                         _instance = new Singleton();
100                     }
101 
102                 }
103             }
104             return _instance;
105 
106         }
107     }
108 
109 
110 
111 
112     public class Person
113     {
114 
115         //把类的构造函数的访问修饰符改为private
116         private Person()
117         {
118             Console.WriteLine(".");
119         }
120 
121         private static Person _instance = null;
122 
123         public static Person GetInstance()
124         {
125             if (_instance == null)
126             {
127                 _instance = new Person();
128             }
129             return _instance;
130         }
131 
132 
133         public string Name { get; set; }
134         public string Email { get; set; }
135         public int Age { get; set; }
136     }
137 }
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