http://blog.csdn.net/bingduanlbd/article/details/8363734
http://www.tuicool.com/articles/Yz2QJn
http://www.cnblogs.com/xing901022/p/3975626.html
http://www.cnblogs.com/cr330326/archive/2016/07/22/5695474.html
http://blog.csdn.net/crazy__chen/article/details/45096623