Regular expression to replace image tag src attribute value

Question

I have a string that contains html code of a document.

It can have multiple image tags inside.

What I want to do is to pass the img tag's src attribute value i.e. url to a C# function and replace that value with the function returns.

How can I do this?

If you could post what you tried so far, it might be easier to understand. — Anirudh Ramanathan, Oct 30 '12 at 13:39
Check this question: http://stackoverflow.com/questions/4257359/regular-expression-to-get-the-src-of-images-in-c-sharp — UnitStack, Oct 30 '12 at 13:44
[You can't parse HTML with regex](http://stackoverflow.com/questions/1732348/regex-match-open-tags-except-xhtml-self-contained-tags) — L.B, Oct 30 '12 at 13:57

Anirudha · Accepted Answer · 2016-01-24T04:02:00.607

3

Regex is not a good for parsing HTML files.HTML is not strict nor is it regular with its format.(for example: in non strict html its OK to have a tag without a closing tag)

Use htmlagilitypack

You can use htmlagilitypack to do it like this

HtmlDocument doc = new HtmlDocument();
doc.Load(yourStream);

foreach(var item in doc.DocumentNode.SelectNodes("//img[@src]"))//select only those img that have a src attribute..ahh not required to do [@src] i guess
{
 item.Attributes["src"].Value=yourFunction(item.Attributes["src"].Value);
}
doc.Save("yourFile");//dont forget to save

edited Jan 24 '16 at 04:02

answered Oct 30 '12 at 13:58

Anirudha

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I am passing HTML in string and I want to return that string with replaced values. I don't want to save it in file. How do I do it? – Dev Oct 31 '12 at 05:00
@DevendraGohil use `doc.DocumentNode.OuterHtml` to get the full html – Anirudha Oct 31 '12 at 07:06

Regular expression to replace image tag src attribute value

1 Answers1