iOS错误：AFNetworking Error Domain=NSURLErrorDomain Code=-999
在stackoverflow.com解释清楚了:
http://stackoverflow.com/questions/7259899/what-to-do-about-an-nsurlerrordomain-999/7260176#7260176
文章来自：http://www.cnblogs.com/tate-zwt/p/5013660.html
在stackoverflow.com解释清楚了:
http://stackoverflow.com/questions/7259899/what-to-do-about-an-nsurlerrordomain-999/7260176#7260176