.net $&替换正则查找到的内容

content = Regex.Replace(content, @"div\s*[^>]*", @"[$&]", RegexOptions.IgnoreCase);

//替换正则取的原字符

 private string Replace(Match m)
        {            
            return m.Value.Replace('<','{').Replace('>','}');
        }

//原字符用<>用{}替换           

MatchEvaluator myEvaluator = new MatchEvaluator(Replace);

content = Regex.Replace(content, @"<p\s*[^>]*>", myEvaluator, RegexOptions.IgnoreCase);