请问我怎么能用ASP.NET截取别个网站的HTML代码,比如我在QQ天气预报http://weather.qq.com/
</a><a target="_blank" href="http://weather.qq.com/preend.htm?dc150.htm">拉萨 阴转多云 -8℃~7℃  小于3级 
</a><a target="_blank" href="http://weather.qq.com/preend.htm?dc166.htm">成都 雾转阴 3℃~10℃  小于3级 
</a><a target="_blank" href="http://weather.qq.com/preend.htm?dc179.htm">昆明 晴 5℃~18℃  小于3级 
在这段代码中我要成都的天气预报.那位大虾能告诉我,高分敬上
</a><a target="_blank" href="http://weather.qq.com/preend.htm?dc150.htm">拉萨 阴转多云 -8℃~7℃  小于3级 
</a><a target="_blank" href="http://weather.qq.com/preend.htm?dc166.htm">成都 雾转阴 3℃~10℃  小于3级 
</a><a target="_blank" href="http://weather.qq.com/preend.htm?dc179.htm">昆明 晴 5℃~18℃  小于3级 
在这段代码中我要成都的天气预报.那位大虾能告诉我,高分敬上
string[] s=rg.GetGroupNames ();
System.Text .RegularExpressions .Match m=rg.Match (htmlstr);
string sss=m.Groups [1].Value .ToString ();