Adding elements to xml fie c# - xmldocument

Question

XmlDocument file:
<?xml version="1.0"?>
<config>
<newsy>
<category id="sport">
<source>
<contelemname>cont</contelemname>
<refresh>3</refresh>
<url>http://sport.wp.pl/rss.xml</url>
</source>
<source>
<contelemname>cont</contelemname>
<refresh>5</refresh>
<url>http://moto.wp.pl/rss.xml</url>
</source>
</category>
</newsy>
</config>
How to add new items to this file like new source(url,refresh) or a new category? Or how to delete category and source.
Code starts with
XDocument doc = XDocument.Load(path);
but whats later?

Answer 1

I like you to take a look at: https://msdn.microsoft.com/en-us/library/ms162365(v=vs.110).aspx, https://msdn.microsoft.com/en-us/library/system.xml.xmlnode(v=vs.110).aspx and https://msdn.microsoft.com/en-us/library/system.xml.xmlnode.appendchild(v=vs.110).aspx
The Microsoft documentation is a great source for these kind of questions.
Load the Xml
You can do this by string
XmlDocument xmlDocument = new XmlDocument();
xmlDocument.LoadXml(xml);
Or by using a file stream (you can use the XDocument you have now)
XmlDocument xmlDocument = new XmlDocument();
using(XmlReader xmlReader = xDocument.CreateReader())
{
xmlDocument.Load(xmlReader);
}
Selecting a node
For this you can use XPath (http://www.w3schools.com/xsl/xpath_syntax.asp, wich returns a XmlNodeList
XmlNodeList categoryNodes = xmlDocument.SelectNodes("config//newsy//category");
Create a new element
For creating a new element u can use the CreateElement method (there are other methods for creating attributes e.t.c. see Microsoft documentation).
XmlNode newSource = xmlDocument.CreateElement("source");
XmlNode newSourceUrl = xmlDocument.CreateElement("url");
newSourceUrl.InnerText = "http://www.test.com";
newSource.AppendChild(newSourceUrl);
This creates a new source element and a url element. the url element will be appended to the source element.
Add it to a category
Add it to a category node.
if (categoryNodes != null && categoryNodes.Count > 0)
categoryNodes[0].AppendChild(newSource);
Search for the node you want to append the child to. You could also check for a certain attribute like so:
foreach (XmlNode node in categoryNodes)
{
if (string.Equals(node.Attributes["id"].Value.ToString(), "sport", StringComparison.OrdinalIgnoreCase))
node.AppendChild(newSource);
}
Save
Save the XmlDocument. To save it to disk:
xmlDocument.Save(path);
The new XML
<?xml version="1.0"?>
<config>
<newsy>
<category id="sport">
<source>
<contelemname>cont</contelemname>
<refresh>3</refresh>
<url>http://sport.wp.pl/rss.xml</url>
</source>
<source>
<contelemname>cont</contelemname>
<refresh>5</refresh>
<url>http://moto.wp.pl/rss.xml</url>
</source>
<source>
<url>http://www.test.com</url>
</source>
</category>
</newsy>
</config>
I hope this helps u.