https://www.jianshu.com/p/f491d0d3c503
http://blog.csdn.net/adparking/article/details/50402980
http://blog.csdn.net/jyf0412/article/details/21900075
https://www.cnblogs.com/luxh/archive/2012/10/15/2724091.html
http://blog.csdn.net/nw_ningwang/article/details/77586602
http://blog.csdn.net/qingzhuoran/article/details/54135444
http://blog.sina.com.cn/s/blog_696c5a5e0101fq63.html