Does .NET framework offer methods to parse an HTML string?

c# .net html parsing

10,804

Solution 1

You can create a dummy html document.

WebBrowser w = new WebBrowser();
w.Navigate(String.Empty);
HtmlDocument doc = w.Document;
doc.Write("<html><head></head><body><img id=\"myImage\" src=\"c:\"/><a id=\"myLink\" href=\"myUrl\"/></body></html>");
Console.WriteLine(doc.Body.Children.Count);
Console.WriteLine(doc.GetElementById("myImage").GetAttribute("src"));
Console.WriteLine(doc.GetElementById("myLink").GetAttribute("href"));
Console.ReadKey();

Output:

file:///c:

about:myUrl

Editing elements:

HtmlElement imageElement = doc.GetElementById("myImage");
string newSource = "d:";
imageElement.OuterHtml = imageElement.OuterHtml.Replace(
        "src=\"c:\"",
        "src=\"" + newSource + "\"");
Console.WriteLine(doc.GetElementById("myImage").GetAttribute("src"));

Output:

file:///d:

Solution 2

Assuming you're dealing with well formed HTML, you could simply treat the text as an XML document. The framework is loaded with features to do exactly what you're asking.

http://msdn.microsoft.com/en-us/library/system.xml.xmldocument.aspx

Solution 3

Aside from the HTML Agility Pack, and porting HtmlUnit over to C#, what sounds like solid solutions are:

Most obviously - use regex. (System.Text.RegularExpressions)
Using an XML Parser. (because HTML is a system of tags treat it like an XML document?)
Linq?

One thing I do know is that parsing HTML like XML may cause you to run into a few problems. XML and HTML are not the same. Read about it: here

Also, here is a post about Linq vs Regex.

10,804

Author by

Jelly Ama

Updated on June 22, 2022

Comments

Jelly Ama almost 2 years
Knowing that I can't use HTMLAgilityPack, only straight .NET, say I have a string that contains some HTML that I need to parse and edit in such ways:
- find specific controls in the hierarchy by id or by tag
- modify (and ideally create) attributes of those found elements
Are there methods available in .net to do so?
porges about 12 years

This requires you to load up the document in a Winforms control.
Jelly Ama about 12 years

Correct me if I'm wrong but this requires a webBrowser control and doesn't allow for direct HTML string parsing.
Alexei Levenkov about 12 years

@JellyAma, yes, but isn't it what you seem to want in "modify (and ideally create) attributes of those found elements"?
Jelly Ama about 12 years

@Alexei, most importantly, I need to parse strings of HTML.
L.B about 12 years

Try to parse this well formed html. <html><body>line1 <br> line2</body></html>
L.B about 12 years

stackoverflow.com/questions/1732348/… stackoverflow.com/questions/1732348/…