http://www.cnblogs.com/willpan/archive/2011/09/26/2176475.html

http://www.cnblogs.com/lip0121/p/4539801.html

通过HttpWebRequest在后台对WebService进行调用

http://www.cnblogs.com/macroxu-1982/archive/2009/12/23/1630415.html

[C#]基于HttpWebRequest和HttpWebResponse的HttpHelper

http://www.cnblogs.com/vanjoge/archive/2011/11/18/2253937.html

http://www.cnblogs.com/yiki/archive/2007/08/28/872528.html

使用 HttpWebRequest 向网站提交数据

http://www.cnblogs.com/webman/archive/2006/11/17/564106.html