C#设计模式之四建造者模式（Builder Pattern）【创建型】

意图：

将一个复杂对象的构建与其表示相分离，使得同样的构建过程可以创建不同的表示。

public class Car{

private IList<string> parts = new List<string>();

public void Add(string part){

parts.Add(part);

} 

 public void Show(){

foreach(var part in parts){

Console.WriteLine("组装"+ part); 

} 

} 

}

 

public abstract class Builder{

public abstract void BuildCarDoor();

public abstract void BuildCarWheel(); 

public abstract Car GetCar(); 

}

 

public class BMWBuilder:Builder{

var car = new Car(); 

public override void BuilderCarDoor(){

 car.Add("add a Door");

} 

public override void BuilderCarWheel(){

car.Add("add a Wheel"); 

} 

public override Car GetCar(){

return car; 

} 

} 

 

public class BYDBuilder:Builder{

var car = new Car();

public override void BuilderCarDoor(){

car.Add("add a Door"); 

} 

public override void BuilderCarWheel(){

car.Add("add a Wheel"); 

} 

public override Car GetCar(){

return car; 

} 

} 

 

public class Director{

public void Construct(Builder builder){

builder.BuilderCarDoor();

builder.BuilderCarWheel(); 

} 

} 

 

public class Client(){

static void Main(){

var director = new Director();

var bmwBuilder = new BMWBuilder();

var bydBuilder = new BYDBuilder();

 

director.Construct(bmwBuilder);

var bmwCar = bmwBuilder.GetCar();

bmwCar.Show();

 

director.Construct(bydBuilder);

var bydCar = bydBuilder.GetCar();

bydCar.Show(); 

} 

} 

 

优点：客户端不必知道产品内部组成的细节。

具体的建造者类之间是相互独立的，容易扩展。 

缺点：产生了多余的Build对象和Dirextor类。