试图从源代码中抓取所有 href。我不明白我做错了什么

Trying to scrape all href from source code. I dont understand what I am doing wrong

我正在尝试从标签中的源代码中抓取所有 href 并使 class = "linked formlink" 。我不明白我在做什么 wrong.I 在 "links".

中得到 null
StreamReader sr = new StreamReader(webBrowser1.DocumentStream);
        string sourceCode = sr.ReadToEnd();
        sr.Close();
        //removing illegal path 

        string regexSearch = new string(Path.GetInvalidFileNameChars()) +        new string(Path.GetInvalidPathChars());
        Regex r = new Regex(string.Format("[{0}]", Regex.Escape(regexSearch)));
        sourceCode = r.Replace(sourceCode, "");

        HtmlAgilityPack.HtmlDocument htmlDoc = new HtmlAgilityPack.HtmlDocument();
        htmlDoc.LoadHtml(sourceCode);

        var links = htmlDoc.DocumentNode
                          .Descendants("a")
                          .Where(x => x.Attributes["class"] != null
                                   && x.Attributes["class"].Value == "linked formlink")
                           .Select(x => x.Attributes["href"].Value.ToString());

正则表达式正在删除括号以及 html-agile-pack 用来确定标签和 类

的其他必要字符

只需删除它