HtmlAgilityPack給出了格式錯誤的HTML的問題

我想從html文檔中提取有意義的文本，並且我使用的是html-agility-pack。這是我的代碼：

string convertedContent = HttpUtility.HtmlDecode(
    ConvertHtml(HtmlAgilityPack.HtmlEntity.DeEntitize(htmlAsString))
);

ConvertHtml：

public string ConvertHtml(string html)
{
    HtmlDocument doc = new HtmlDocument();
    doc.LoadHtml(html);

    StringWriter sw = new StringWriter();
    ConvertTo(doc.DocumentNode, sw);
    sw.Flush();
    return sw.ToString();
}

轉換成：

public void ConvertTo(HtmlAgilityPack.HtmlNode node, TextWriter outText)
{
    string html;
    switch (node.NodeType)
    {
        case HtmlAgilityPack.HtmlNodeType.Comment:
            // don't output comments
            break;

        case HtmlAgilityPack.HtmlNodeType.Document:
            foreach (HtmlNode subnode in node.ChildNodes)
            {
              ConvertTo(subnode, outText);
            }
            break;

        case HtmlAgilityPack.HtmlNodeType.Text:
            // script and style must not be output
            string parentName = node.ParentNode.Name;
            if ((parentName == "script") || (parentName == "style"))
                break;

            // get text
            html = ((HtmlTextNode)node).Text;

            // is it in fact a special closing node output as text?
            if (HtmlNode.IsOverlappedClosingElement(html))
                break;

            // check the text is meaningful and not a bunch of whitespaces
            if (html.Trim().Length > 0)
            {
                outText.Write(HtmlEntity.DeEntitize(html) + " ");
            }
            break;

        case HtmlAgilityPack.HtmlNodeType.Element:
            switch (node.Name)
            {
                case "p":
                    // treat paragraphs as crlf
                    outText.Write("\r\n");
                    break;
            }

            if (node.HasChildNodes)
            {
            foreach (HtmlNode subnode in node.ChildNodes)
             {
              ConvertTo(subnode, outText);
             }
            }
            break;
    }
}

現在在某些情況下，當html頁面格式不正確時（例如，以下頁面 - http://rareseeds.com/cart/products/Purple_of_Romagna_Artichoke-646-72.html有一個格式錯誤的元標記，如<meta content="text/html; charset=uft-8" http-equiv="Content-Type"> ）[注意”uft“而不是utf]我的代碼在我嘗試加載html文檔時正在嘔吐。

有人可以建議我如何克服這些格式錯誤的HTML頁面並仍然從html文檔中提取相關文本？

謝謝，卡皮爾