一种多态的实现方法

通过 Activator.CreateInstance 以及  继承关系实现

    public interface Name{String GetName();}public class Join : Name{public string GetName(){return "Join";}}public class Thomas : Name{public string GetName(){return "Thomas";}}public class RecongisePerson{Hashtable nameTable = new Hashtable();public void SetNameList(String name, Type type){nameTable[name] = type;}public String GetName(String person){Name b = (Name)Activator.CreateInstance((Type)nameTable[person]);String s = b.GetName();return s;}}