Singleton模式

最新推荐文章于 2022-05-16 16:55:08 发布

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本文深入探讨了单例模式的不同实现方式，包括简单的单例模式、线程安全的单例模式（单重锁定与双重锁定）、静态初始化单例及延迟初始化单例等。每种实现都附带了详细的代码示例，帮助读者理解各种单例模式的特点及其适用场景。

主程序

using System; using System.Text; namespace SafeSingletonDemo { class Program { static void Main(string[] args) { DelayInitialization s1 = DelayInitialization.Instance; DelayInitialization s2 = DelayInitialization.Instance; if (s1 == s2) { Console.WriteLine("{0}与{1}创建了同一个实例！", s1, s2); } Console.ReadLine(); } } }

简单Singleton

using System; namespace SafeSingletonDemo { public sealed class OrginalSingleton { private static OrginalSingleton instance; private OrginalSingleton() { } public static OrginalSingleton Instance { get { if (instance == null) { instance = new OrginalSingleton(); } return instance; } } } }

线程安全Singleton

using System; namespace SafeSingletonDemo { /// <summary> /// 安全线程单件模式：单重锁定 /// </summary> public sealed class SingleLockedSingleton { private static SingleLockedSingleton instance; private static readonly Object obj = new object(); private SingleLockedSingleton() { } public static SingleLockedSingleton Instance { get { lock (obj) { if (instance == null) { instance = new SingleLockedSingleton(); } return instance; } } } } }

双重加锁Singleton

using System; namespace SafeSingletonDemo { /// <summary> /// 安全线程单件模式：双重锁定 /// </summary> public sealed class DoubleLockedSingleton { private static DoubleLockedSingleton instance; private static readonly Object obj = new object(); private DoubleLockedSingleton() { } public static DoubleLockedSingleton Instance { get { if (instance == null) { lock (obj) { if (instance == null) { instance = new DoubleLockedSingleton(); } } } return instance; } } } }

静态初始化Singleton

using System; namespace SafeSingletonDemo { public sealed class StaticInitialization { private static readonly StaticInitialization instance = new StaticInitialization(); private StaticInitialization() { } public static StaticInitialization Instance { get { return instance; } } } }

延迟初始化Singleton

using System; namespace SafeSingletonDemo { public sealed class DelayInitialization { DelayInitialization() { } public static DelayInitialization Instance { get { return Nested.instance; } } class Nested { static Nested() { } internal static readonly DelayInitialization instance = new DelayInitialization(); } } }