建造者模式

建造者模式

将复杂的对象的实现过程与表现形式进行分离。

此模式用于创建一些复杂的对象，内部建造顺序稳定，但是建造的内容有复杂的变化。此模式将建造代码与表示代码分离，建造者隐藏了产品的组装过程，通过不同的建造者定义不同的产品内部表示。

Builder.PNG

class Program
    {
        static void Main(string[] args)
        {
            Director director = new Director();
            Builder builder = new DellWorker();
            director.CreateComputer(builder);
            Computer computer = builder.GetComputer();
            computer.Show();
        }
    }
    class Computer
    {
        List<string> computerCom =new List<string>(); 
        public void Add(string com)
        {
            computerCom.Add(com);
        }
        public void Show()
        {
            foreach(var item in computerCom)
            {
                Console.WriteLine("Build : "+ item);
            }
        }
    }
    abstract class Builder
    {
        protected Computer computer = new Computer();
        public abstract void AddCPU();
        public abstract void AddGPU();
        public abstract void AddRAM();
        public abstract Computer GetComputer();
    }
    class DellWorker : Builder
    {
        public override void AddCPU()
        {
            computer.Add("INTELCPU");
        }

        public override void AddGPU()
        {
            computer.Add("NAVIDGPU");
        }

        public override void AddRAM()
        {
            computer.Add("CRAM");
        }

        public override Computer GetComputer()
        {
            return computer;
        }
    }
    class Director
    {
        
        public void CreateComputer(Builder builder)
        {
            builder.AddCPU();
            builder.AddGPU();
            builder.AddRAM();
        }
    }

Lua实现：

-- [[将复杂的对象的实现过程与表现形式进行分离。]]
Product = {}
function Product:new(o)
    o = o or {};
    setmetatable(o,self);
    self.__index = self;
    return o;
end
function Product:Show()
    print(self.unit);
end

Builder = {}
function Builder:new(o)
    o = o or {};
    setmetatable(o,self);
    self.__index = self;
    return o;
end 

ComputerBuilder = Builder:new();
function ComputerBuilder:new(o)
    o = o or {}
    setmetatable(o,self)
    o.product = Product:new();
    self.__index = self;
    return o;
end

function ComputerBuilder : AddCpu()
    if self.product.unit == nil then
        self.product.unit = "Computer :";
    end
    self.product.unit = self.product.unit .. "英特尔CPU9900k; ";
end
function ComputerBuilder : AddGpu()
    self.product.unit = self.product.unit .. "GPU2080TI; ";
end
function ComputerBuilder : AddRAM()
    self.product.unit = self.product.unit .. "RAM64G; ";
end

Director = {}
function Director:new(o)
    o = o or {};
    setmetatable(o,self);
    self.__index = self;
    return o;
end
function Director:Construct(builder)
    if builder ~= nil then
        builder:AddCpu();
        builder:AddGpu();
        builder:AddRAM();
        builder.product:Show();
    end
end

combuilder = ComputerBuilder : new();
comDirector = Director:new();
comDirector = Director:Construct(combuilder);