http://www.manew.com/thread-36420-1-1.html?_dsign=4be49d78
http://www.jb51.net/article/87529.htm
http://blog.csdn.net/suifcd/article/details/42869341
http://www.cnblogs.com/Shoring/p/4762647.html
排序：http://www.cnblogs.com/xiaoyi115/archive/2011/05/15/2047017.html
