状态模式定义：
英文定义：The State Pattern allows an object to alter its behavior when its internal state changes. The object will appear to change its class.
中文定义：当一个对象的内在状...
状态模式
状态模式结构：
1 using System;
2 using System.Collections.Generic;
3 using System.Linq;
4 using System.Text;
5 using System.Threading.Tasks;
6
7 namespace DesignPattern....
