Retrieve document content

Get Document Object

1. Create Document Object

HtmlDocument document = new HtmlDocument();Code language: JavaScript (javascript)

2. Two Loading Methods

1）Load HTML string

document.LoadHtml(htmlString);Code language: JavaScript (javascript)

2）Load local HTML file (specify encoding to avoid garbled text)

document.Load(@"c:/news.html", Encoding.UTF8);Code language: JavaScript (javascript)

For Windows paths, it’s recommended to use @ to disable escaping; c://news.html in the material is just a writing example.

3. Get Root Node

HtmlNode rootNode = document.DocumentNode;Code language: JavaScript (javascript)

All xpath queries run against rootNode.

Node Operations

1. Create New Node From Node HTML

HtmlNode newNode = HtmlNode.CreateNode(newsNode.OuterHtml);

• OuterHtml：Includes self‑tag plus all inner HTML content
• Commonly used for node duplication and parsing partial HTML snippets

2. Query Nodes

• SelectSingleNode("XPath")：Matches the first node, returns HtmlNode

HtmlNode childNode = itemNode.SelectSingleNode("//div[1]");Code language: JavaScript (javascript)

• SelectNodes("XPath")：Matches all qualifying nodes, returns HtmlNodeCollection

3. Read Text and Attributes

1. Get plain text inside node

string text = itemNode.InnerText;

2. Read tag attribute (basic pattern)

string href = itemNode.Attributes["href"].Value;Code language: JavaScript (javascript)

Warning: If the tag has no href attribute, directly accessing Attributes["href"] yields null and triggers runtime exceptions.

Safe approach recommended:

string href = itemNode.GetAttributeValue("href", "");Code language: JavaScript (javascript)

4. Full Sample: Iterate News List

foreach (HtmlNode item in newsList)
{
    string title = item.InnerText;
    string href = item.Attributes["href"].Value;
}Code language: PHP (php)

Additional Notes

1. Null Handling
   SelectNodes() returns null when zero nodes match. Always validate before foreach iteration:

if(newsList != null)
{
    foreach(var item in newsList){ ... }
}Code language: PHP (php)

2. Differentiate InnerText / InnerHtml / OuterHtml

• InnerText：Extracts only text content, strips all markup tags
• InnerHtml：Inner HTML of node, excludes its own opening‑closing tag
• OuterHtml：Self‑tag plus all inner HTML markup

2. XPath Tips
   //div performs global search for all div elements; omit // to match only direct child nodes.

Complete Working Example

using HtmlAgilityPack;
using System.Text;

//1.Initialize document
HtmlDocument document = new HtmlDocument();
document.Load("news.htm", Encoding.UTF8);
HtmlNode rootNode = document.DocumentNode;

//2.Batch fetch news links
HtmlNodeCollection newsList = rootNode.SelectNodes(@"//div[@class='blk122']/a");

if(newsList != null)
{
    foreach (HtmlNode item in newsList)
    {
        string title = item.InnerText.Trim();
        string link = item.GetAttributeValue("href", "");
        Console.WriteLine($"Title：{title} Link：{link}");
    }
}Code language: JavaScript (javascript)

Retrieve document content