获取特殊URL链接源码的问题

[ganzilong]

我想获取http://taoke.alimama.com/rpc/searchAuctionByRpc.do?pw=%71%58%73%6f%78%2b%77%3d&rowoffset=1&rowcount=40&keyword=Nike此链接的源文件，用ASP，PHP都可以轻松获取，但用ASP.NET的WebClient,HttpWebRequest都无法取到数据，原因在于pw=后的"%71%58%73%6f%78%2b%77%3d"在用HttpWebRequest,WebClient时，URL都会将那串字符转成qXsox+w=，而我URL请求的必须是UrlEncode(qXsox+w=)后的字符串，我试着将"%71%58%73%6f%78%2b%77%3d"再UrlEncode一次，转成"%25%37%31%25%35%38%25%37%33%25%36%66%25%37%38%25%32%62%25%37%37%25%33%64"，结果还是不行，HttpWebRequest,WebClient请求的URL变成了"%2571%2558%2573%256f%2578%252b%2577%253d",那个%25又无法转义为%.望各们高手出手帮帮小弟我。