Question

Currently I use .Net WebBrowser.Document.Images() to do this. It requires the Webrowser to load the document. It’s messy and takes up resources.

According to this question XPath is better than a regex at this.

Anyone know how to do this in C#?

Answer 1

If your input string is valid XHTML you can treat is as xml, load it into an xmldocument, and do XPath magic 🙂 But it’s not always the case.

Otherwise you can try this function, that will return all image links from HtmlSource :

public List<Uri> FetchLinksFromSource(string htmlSource) {     List<Uri> links = new List<Uri>();     string regexImgSrc = @'<img[^>]*?src\s*=\s*[''']?([^''' >]+?)[ '''][^>]*?>';     MatchCollection matchesImgSrc = Regex.Matches(htmlSource, regexImgSrc, RegexOptions.IgnoreCase | RegexOptions.Singleline);     foreach (Match m in matchesImgSrc)     {         string href = m.Groups[1].Value;         links.Add(new Uri(href));     }     return links; } 

And you can use it like this :

HttpWebRequest request = (HttpWebRequest)WebRequest.Create('http://www.example.com'); request.Credentials = System.Net.CredentialCache.DefaultCredentials; HttpWebResponse response = (HttpWebResponse)request.GetResponse(); if (response.StatusCode == HttpStatusCode.OK) {     using(StreamReader sr = new StreamReader(response.GetResponseStream()))     {         List<Uri> links = FetchLinksFromSource(sr.ReadToEnd());     } }