正则匹配获得匹配值

 Regex reg = new Regex(@"(?is)<a\s+(?:(?<key>[^\s=]+)=(?<value>[^\s>]+)\s*)+>(?<text>(?:(?!</?a\b).)*)</a>");
            MatchCollection mc = reg.Matches(html);
            List<CategoryInfo> ctg = null;
            if (mc.Count > 0)
            {
                ctg = new List<CategoryInfo>();
                foreach (Match m in mc)
                {
                    string v = m.Groups["value"].Value;
                    string t = m.Groups["text"].Value;
                 }
             }