https://github.com/maxzhang/maxzhang.github.com/issues/8
http://www.cnblogs.com/leejersey/p/4220588.html ;
http://blog.csdn.net/sweetsuzyhyf/article/details/44195549/

下拉刷新
http://www.cnblogs.com/sword-successful/archive/2015/06/30/4609498.html ;