这里有个 非常好的分析 html的 类。
节约了不少时间。

项目地址
http://www.codeplex.com/Wiki/View.aspx?ProjectName=htmlagilitypack

For example, here is how you would fix all hrefs in an HTML file:

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");

If you want to participate to the project - because that's the whole purpose of putting the source there, right - use the forums or drop me a note (simon underscore mourier at hotmail dot com)!

Happy coding, scraping, scanning, html-ing, xhtml-ing, etc... :^)
Simon Mourier.