建造者模式 c#

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;

namespace ConsoleApplication1
{
class Program
{

public class Product
{
private string name;

public string Name
{
get { return name; }
set { name = value; }
}

public override string ToString()
{
return string.Format("Name: {0}", name);
}
}

public abstract class Builder
{
public abstract void SetName(string name);
public abstract Product GetProduct();
}

public class ConcreateBuilder : Builder
{
private Product product = new Product();

public override void SetName(string name)
{
product.Name = name;
}

public override Product GetProduct()
{
return product;
}
}

public class Director
{
private Builder builder = new ConcreateBuilder();

public Product GetAProduct()
{
builder.SetName("a");
return builder.GetProduct();
}

public Product GetBProduct()
{
builder.SetName("b");
return builder.GetProduct();
}
}

static void Main(string[] args)
{
Director director = new Director();
Product a = director.GetAProduct();
Product b = director.GetBProduct();

Console.WriteLine(a.ToString());
Console.WriteLine(b.ToString());
}
}
}