在html中找到所有链接，然后继续搜索该链接（Asp.net Core）

Question

我需要输入值并进行搜索链接，找到html中的单词和链接。

如果存在单词，则显示消息并继续在找到的链接中监视该单词并显示消息，如果不存在，则显示消息并继续在找到的油墨中搜索单词。

单词和起始网址是从输入中获取的。

我实现了从链接的html中获取单词并显示消息的方法 这是它的代码。

 [HttpPost]
    public JsonResult SearchWord([FromBody] RequestModel model){
        string result;
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(model.adress);
        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream receiveStream = response.GetResponseStream();
            StreamReader readStream = null;

            if (response.CharacterSet == null)
            {
                readStream = new StreamReader(receiveStream);
            }
            else
            {
                readStream = new StreamReader(receiveStream, Encoding.GetEncoding(response.CharacterSet));
            }

            string data = readStream.ReadToEnd();
            string pattern = model.word;

            // Instantiate the regular expression object.
            Regex r = new Regex(pattern, RegexOptions.IgnoreCase);

             // Match the regular expression pattern against your html data.
            Match m = r.Match(data);

            if (m.Success)
            {
                result = "Word  "+model.word+"  finded in  "+ model.adress;
            }
            else{
                result = "Word not finded";
            }
            response.Close();
            readStream.Close();
            return Json(result);

    }

如何获取所有链接并继续在其中搜索单词？