public class Program{public static void Main(string[] args){var build = new BuildSystem(new ModernFactory());build.Build();Console.ReadKey();}}/// <summary>/// 抽象道路/// </summary>public abstract class Road{/// <summary>/// 该抽象方法,没有实际意义,只为演示效果/// </summary>/// <returns></returns>public abstract string ShowMessage();}/// <summary>/// 现代化道路/// </summary>public class ModernRoad : Road{public override string ShowMessage(){return "I am Modern Road";}}/// <summary>/// 抽象房屋/// </summary>public abstract class House{/// <summary>/// 该抽象方法,没有实际意义,只为演示效果/// </summary>/// <returns></returns>public abstract string ShowMessage();}/// <summary>/// 现代化房屋/// </summary>public class ModernHouse : House{public override string ShowMessage(){return "I am Modern House";}}/// <summary>/// 前面的随笔中说过,抽象工厂是为了解决系列抽象对象的创建,所以里面会有>1个抽象对象的创建方法/// </summary>public abstract class AbstractFactory{public abstract Road CreateRoad();public abstract House CreateHouse();}/// <summary>/// 现代化房屋和道路的创建工厂/// </summary>public class ModernFactory : AbstractFactory{public override House CreateHouse(){return new ModernHouse();}public override Road CreateRoad(){return new ModernRoad();}}/// <summary>/// 构建系统/// </summary>public class BuildSystem{private AbstractFactory _abstractFactory;public BuildSystem(AbstractFactory abstractFactory){_abstractFactory = abstractFactory;}public void Build(){var house=_abstractFactory.CreateHouse();var road=_abstractFactory.CreateRoad();Console.WriteLine($"{house.ShowMessage()},现已被创建");Console.WriteLine($"{road.ShowMessage()},现已被创建");}}

    public class Program{public static void Main(string[] args){new BuildSystem().Build();Console.ReadKey();}}public abstract class Road{public abstract string ShowMessage();}public class ModernRoad : Road{public override string ShowMessage(){return "I am Modern Road";}}public class Factory<T> where T : class{public static T Get(){return _create.Create();}static ICreator _create;interface  ICreator{T Create();}class Creator<TChild> : ICreator where TChild:T,new(){public  T Create(){return new TChild();}}class SingletonCreator<TChild> : ICreator where TChild : T, new(){/// <summary>/// 初始化TChild的时候会调用static构造函数,所以线程安全./// </summary>static readonly T Instance = new TChild();public T Create(){//这里单例可以使用双检锁创建单例对象,也可以使用"内联初始化"来创建单例对象return Instance;}}/// <summary>/// 支持继承关系的Set方法/// </summary>/// <typeparam name="TChild"></typeparam>public static void Set<TChild>() where TChild:T,new(){_create = new Creator<TChild>();}/// <summary>/// 支持单例同时支持继承的Set方法/// </summary>/// <typeparam name="TChild"></typeparam>public static void SetSingleton<TChild>() where TChild : T, new(){_create = new SingletonCreator<TChild>();}}/// <summary>/// 构建系统/// </summary>public class BuildSystem{public void Build(){//注册ModernRoad对象,Transiant模式Factory<Road>.Set<ModernRoad>();var r1=Factory<Road>.Get().GetHashCode();var r2= Factory<Road>.Get().GetHashCode();Console.WriteLine("r1和r2引用" + (ReferenceEquals(r1, r2) ? "相等" : "不相等"));//注册ModernRoad对象,单例模式Factory<Road>.SetSingleton<ModernRoad>();var s1 = Factory<Road>.Get();var s2 = Factory<Road>.Get();Console.WriteLine("s1和s2引用"+(ReferenceEquals(s1, s2)?"相等":"不相等")); }}