HttpContext讲解

http://www.cnblogs.com/scy251147/p/3549503.html

http://www.360doc.com/content/14/0526/10/17655805_381044549.shtml

http://www.cnblogs.com/qiufuwu618/archive/2012/11/05/2755411.html

http://blog.csdn.net/jingmeifeng/article/details/7787949