如何使用 asp.net 从网页中抓取数据

我想从我的html页面获取值。我试图使用 HttpWebRequest 获得相同的结果，但到目前为止我无法做到这一点，请帮助？

    <div class="container">
        <div class="one-third column">
<ol start="181">
<li><a href="/lyrics/hindi-lyrics-of-Aaye%20Din%20Bahar%20Ke.html">Aaye Din Bahar Ke</a>
</li><li><a href="/lyrics/hindi-lyrics-of-Aayega%20Aane%20Wala.html">Aayega Aane Wala</a>
</li><li><a href="/lyrics/hindi-lyrics-of-Aayi%20Milan%20Ki%20Raat.html">Aayi Milan Ki Raat</a>
</li><li><a href="/lyrics/hindi-lyrics-of-Aiyyaa.html">Aiyyaa</a>
</li><li><a href="/lyrics/hindi-lyrics-of-Ajab%20Gazabb%20Love.html">Ajab Gazabb Love</a>
</li></ol>
    </div>
<div class="sixteen columns">
<hr>
More Pages: 
<a href="hindi-songs-starting-A.html">1</a> : <a href="hindi-songs-starting-A-page-2.html">2</a> : 3 : <a href="hindi-songs-starting-A-page-4.html">4</a> : <a href="hindi-songs-starting-A-page-5.html">5</a> : <a href="hindi-songs-starting-A-page-6.html">6</a> : 
        <hr>
<center>
<h4>Hindi Lyrics By Movie Title</h4>
<p>         
<a href="/lyrics/hindi-songs-starting-0.html">0-9</a>
<a href="/lyrics/hindi-songs-starting-A.html">A</a>
<a href="/lyrics/hindi-songs-starting-B.html">B</a>
<a href="/lyrics/hindi-songs-starting-W.html">W</a>
X
<a href="/lyrics/hindi-songs-starting-Y.html">Y</a>
<a href="/lyrics/hindi-songs-starting-Z.html">Z</a>
 | <a href="http://www.hindilyrics.net/songs/">Top Songs</a>
</p>
</center>
    </div>

这是我的 HTML 我想获取所有链接

string urls = "your web page";
        string result = string.Empty;
        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(urls);
        request.UserAgent = @"Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko/20091102 Firefox/3.5.5";
        using (var stream = request.GetResponse().GetResponseStream())
        using (var reader = new StreamReader(stream, Encoding.UTF8))
        {
            result = reader.ReadToEnd();
        }
        HtmlAgilityPack.HtmlDocument doc = new HtmlAgilityPack.HtmlDocument();
        doc.Load(new StringReader(result));
        var elements = doc.DocumentNode.SelectNodes("//div[@class='one-third column']");
        foreach (HtmlNode item in elements)
        {
            var node1 = item.SelectNodes(".//li");
            foreach (HtmlNode li in node1)
            {
                var a = li.SelectSingleNode("//a").Attributes["href"].Value;//your link
            }
        }