ASiHttpRequest:
http://blog.csdn.net/zkdemon/article/details/7066807
http://blog.csdn.net/fengsh998/article/details/8443540
http://blog.csdn.net/marujunyy/article/details/8474518
MKNetworkKit:
http://blog.csdn.net/marujunyy/article/details/8495810