HtmlAgilityPack example for changing links doesn't work. How do I accomplish this?

The example on codeplex is this :

HtmlDocument doc = new HtmlDocument();
 doc.Load("file.htm");
 foreach(HtmlNode link in doc.DocumentElement.SelectNodes("//a[@href"])
 {
    HtmlAttribute att = link["href"];
    att.Value = FixLink(att);
 }
 doc.Save("file.htm");

The first issue is HtmlDocument.DocumentElement does not exist! What does exist is HtmlDocument.DocumentNode but even when I use that instead, I'm unable to access the href attribute as described. I get the following error:

Cannot apply indexing with [] to an expression of type 'HtmlAgilityPack.HtmlNode'

Here's the code I'm trying to compile when I get this error:

private static void ChangeUrls(ref HtmlDocument doc)
{
 开发者_JAVA百科   foreach(HtmlNode link in doc.DocumentNode.SelectNodes("//@href"))
    {
        HtmlAttribute attr = link["href"];
        attr.Value = Rewriter(attr.Value);
    }
}

UPDATE: I Just found that the example was never meant to work...And I've got a solution after reading the example code...I'll post my solution for other people like me to enjoy once completed.

Here's my quick solution based on portions of the sample code included in the ZIP.

private static void ChangeLinks(ref HtmlDocument doc)
        {
            if (doc == null) return;
            //process all tage with link references
            HtmlNodeCollection links = doc.DocumentNode.SelectNodes("//*[@background or @lowsrc or @src or @href]");
            if (links == null)
                return;

            foreach (HtmlNode link in links)
            {

                if (link.Attributes["background"] != null)
                    link.Attributes["background"].Value = _newPath + link.Attributes["background"].Value;
                if (link.Attributes["href"] != null)
                    link.Attributes["href"].Value = _newPath + link.Attributes["href"].Value;(link.Attributes["href"] != null)
                    link.Attributes["lowsrc"].Value = _newPath + link.Attributes["href"].Value;
                if (link.Attributes["src"] != null)
                    link.Attributes["src"].Value = _newPath + link.Attributes["src"].Value;
            }
        }