1. 简介

　　工厂方法：符合依赖倒置原则、单一职责、开闭原则。

　　与简单工厂的区别：简单工厂是在一个工厂里生成多个不同的类，而工厂方法是一个对象对应一个生成工厂，这些工厂都实现了一个共同的接口IFactory，很好的符合了依赖倒置原则、单一职责、开闭原则， 每个工厂只负责创建对象。

2. 核心代码

1   public interface IFactory2     {3         IPeople CreateInstance();4     }

1   public class ChineseFactory : IFactory2     {3         public IPeople CreateInstance()4         {5             return new Chinese();6         }7     }

1   public class JanpaneseFactory : IFactory2     {3         public IPeople CreateInstance()4         {5             return new Janpanese();6         }7     }

1  public class AmericaFactory : IFactory2     {3         public IPeople CreateInstance()4         {5             return new America();6         }7     }

1 static void Main(string[] args) 2         { 3             IFactory iFactory1 = new ChineseFactory(); 4             IFactory iFactory2 = new AmericaFactory(); 5             IFactory iFactory3 = new JanpaneseFactory(); 6  7             IPeople iPeople1 = iFactory1.CreateInstance(); 8             IPeople iPeople2 = iFactory2.CreateInstance(); 9             IPeople iPeople3 = iFactory3.CreateInstance();10 11 12             iPeople1.Eating();13             iPeople2.Eating();14             iPeople3.Eating();15 16             Console.ReadKey();17 18         }