在C＃中的html文档中插入新节点

Question

I am trying to insert new node in the document using htmlagilitypack. I am reading the document from the stream , insert the node and then return the document as a FileContentResult object :

HtmlDocument ndoc = new HtmlDocument();
ndoc.Load(stream);

HtmlNode usern = HtmlNode.CreateNode("<img .... />");
usern.Attributes.Add("onclick", "javascript:document.location.href='/Home/Index';");
ndoc.DocumentNode.SelectSingleNode("id('main')").AppendChild(usern);

using (MemoryStream ms = new MemoryStream())
{
   ndoc.Save(ms);
   ms.Seek(0, System.IO.SeekOrigin.Begin);
   fileBytes = ms.ToArray();
}

FileContentResult file = File(fileBytes, "text/html");
return file;

Problem : New node ( img ) is not inserting. My footer content gone if i am using this code and if i just read the document from the stream and return as a FileContentResult then everything perfect. I want to know whats the problem with this code or where i am doing wrong ?

Answer 1

Take a look at HTML Agility pack create new HTMLNode .

This shows how to properly create a new node. In my experience, their code works fine. Similar to jQuery taking it step by step. Good luck!

Answer 2

try to change

HtmlNode usern = HtmlNode.CreateNode("<img .... />");

to just img

HtmlNode usern = HtmlNode.CreateNode("<img></img>");

and add this

 ndoc.OptionWriteEmptyNodes = true;

Answer 3

I came across the same issue, resolved it by passing the clone object. just modify the line

ndoc.DocumentNode.SelectSingleNode("id('main')").AppendChild(usern);

to

ndoc.DocumentNode.SelectSingleNode("id('main')").AppendChild(usern.CloneNode(true));