string html = new xkHttp().httpGET("http://www.xiake.me/bbs/", xkCookies.GetCookie(), "", Encoding.GetEncoding("utf-8"));//存放提取出的URL
NodeFilter filter = new HasAttributeFilter("name", "keywords");
NodeList htmlNodes = new Parser(new Lexer(html)).Parse(filter);
ITag t = (MetaTag)htmlNodes[0];
MessageBox.Show(htmlNodes.Count.ToString());

这样下来，就可以得到你想要的内容了。