C# 建造者模式（Builder Pattern）

建造者模式（Builder Pattern），也被称为生成器模式，是一种对象构建模式，旨在将复杂对象的构建过程与表示分离，使得同样的构建过程可以创建不同的表示。这种模式特别适用于构建具有多个组成部分的复杂对象，且这些组成部分的创建和组装方式相对独立。

public class BuilderPatternTest
{public void Main(){var director = new Director();//指挥者1var director1 = new Director1();//指挥者2var desktopBuilder = new DesktopBuilder();//建造者1var desktopBuilder2 = new DesktopBuilder2();//建造者2//第一台电脑，使用指挥者1，使用建造者1var computer1 = director.Construct(desktopBuilder);Console.WriteLine(computer1.ToString());//第二台电脑，使用指挥者2，使用建造者2var computer2 = director1.Construct(desktopBuilder);Console.WriteLine(computer2.ToString());//第三台电脑，使用指挥者1，使用建造者2var computer3 = director.Construct(desktopBuilder2);Console.WriteLine(computer3.ToString());//第四台电脑，使用建造者1,不使用指挥者var computer4 = new DesktopBuilder().SetType("平板电脑").SetRam(256).SetProcessor("i13212").Build();Console.WriteLine(computer4.ToString());}
}// 定义产品类
public class Computer
{public string Type { get; }public bool IsGraphicsCardIncluded { get; }public int Ram { get; }public string Processor { get; }public Computer(string type, bool isGraphicsCardIncluded, int ram, string processor){Type = type;IsGraphicsCardIncluded = isGraphicsCardIncluded;Ram = ram;Processor = processor;}public override string ToString(){return $"Type: {Type}, Graphics Card: {IsGraphicsCardIncluded}, RAM: {Ram}GB, Processor: {Processor}";}
}// 抽象建造者
// 也可以使用接口实现抽象建造者
// 方法中返回自身，以便链式调用
public abstract class Builder
{protected string Type;protected bool IsGraphicsCardIncluded;protected int Ram;protected string Processor;public abstract Computer Build();public virtual Builder SetType(string type){return this;}public virtual Builder SetGraphicsCard(bool isGraphicsCardIncluded){return this;}public virtual Builder SetRam(int ram){return this;}public virtual Builder SetProcessor(string processor){return this;}
}// 具体建造者
public class DesktopBuilder : Builder
{public override Computer Build(){return new Computer(Type, IsGraphicsCardIncluded, Ram, Processor);}public override DesktopBuilder SetType(string type){Type = type;return this;}public override DesktopBuilder SetGraphicsCard(bool isGraphicsCardIncluded){IsGraphicsCardIncluded = isGraphicsCardIncluded;return this;}public override DesktopBuilder SetRam(int ram){Ram = ram;return this;}public override DesktopBuilder SetProcessor(string processor){Processor = processor;return this;}
}public class DesktopBuilder2 : Builder
{public override Computer Build(){return new Computer(Type, IsGraphicsCardIncluded, Ram, Processor);}public override DesktopBuilder2 SetType(string type){Type = type;return this;}public override DesktopBuilder2 SetGraphicsCard(bool isGraphicsCardIncluded){IsGraphicsCardIncluded = isGraphicsCardIncluded;return this;}public override DesktopBuilder2 SetRam(int ram){Ram = ram;return this;}
}// 导演类
public class Director
{public Computer Construct(Builder builder){builder.SetType("台式电脑");builder.SetGraphicsCard(true);builder.SetRam(16);builder.SetProcessor("i7");return builder.Build();}
}public class Director1
{public Computer Construct(Builder builder){builder.SetType("笔记本电脑");builder.SetGraphicsCard(true);builder.SetRam(128);builder.SetProcessor("i1000");return builder.Build();}
}