如何在不使用第三方库的情况下从HTML提取文本？

Question

_request = (HttpWebRequest)WebRequest.Create(url);
_response = (HttpWebResponse) _request.GetResponse();
StreamReader streamReader = new StreamReader(_response.GetResponseStream());
string text = streamReader.ReadToEnd();

Text with html tags. How i can get text without html tags?

Answer 1

How do you extract text from dynamic HTML without using 3rd party libraries? Simple, you invent your own HTML parsing library using the string parsing functions present in the .NET framework.

Seriously, doing this by yourself is a bad idea. If you're pulling dynamic HTML off the web, you have to be prepared for different closing tags, mismatched tags, missing end tags, and so forth. Unless you have a really good reason why you need to write one yourself, just use HTML Agility Pack , and let that do the hard work for you.

Also, make sure you're not succumbing to Not Invented Here Syndrome .

Answer 2

You might want to take a look at HTMLAgilityPack .

It's a great free .net lib, which enables you to load and parse HTML. Enjoy.

Answer 3

Try this:

System.Xml.XmlDocument docXML = new System.Xml.XmlDocument();
docXML.Load(url);
string textWithoutTags = docXML.InnerText;

Be happy :)

Answer 4

This question has been asked before. There are a few ways to do it, including using a Regular Expression or as pointed out by Adrian, the Agility Pack.

See this question: How can I strip HTML tags from a string in ASP.NET?

Answer 5

1) Do not use Regular Expressions. (see this great StackOverflow post: RegEx match open tags except XHTML self-contained tags )

2) Use HtmlAgilityPack. But I see you do not want 3rd Party libraries, so we are forced to....

3) Use XmlReader . You can pretty much use the example code straight from MSDN, and just ignore all cases of XmlNodeType except for XmlNodeType.Text . For that case simply write your output to a StreamWriter.