http://www.jianshu.com/p/169e31cacf42

http://www.jianshu.com/p/7f8472a97aa6 

https://segmentfault.com/a/1190000004237771

 

 

 

 

 

App Extension

 

http://www.jianshu.com/p/aa1d5bf7cc47

 

http://www.cnblogs.com/xdream86/p/3855932.html