缓存，接口，枚举，抽象类

 解释C#基础之接口

https://www.cnblogs.com/Mryang-blog-cn/p/cxl.html       

https://www.cnblogs.com/fangyz/p/5259619.html

缓存

https://www.cnblogs.com/wangjifeng23/p/9626119.html  

https://www.cnblogs.com/armyfai/p/3631152.html  

缓存帮助类

httpruntime     https://www.cnblogs.com/luofuxian/p/9447008.html