全部模式解说：http://www.runoob.com/design-pattern/design-pattern-tutorial.html
进阶：http://www.cnblogs.com/Terrylee/category/36516.html
委托、观察者：
http://www.tracefact.net/CSharp-Programming/Delegates-and-Events-in-CSharp.aspx
http://www.cnblogs.com/joy99/p/7354233.html
http://www.cnblogs.com/joy99/p/7012770.html
