C# parse XML File

c# xml parsing .net-4.0

11,671

Solution 1

You could use XPath expression for that. Below is complete example on console-appliactaion - as you use xlmns namespace, it requries a little modification of ParseXML method.

using System;
using System.Xml;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            XmlDocument xmlDocument = new XmlDocument();
            xmlDocument.Load("XMLFile1.xml");
            XmlNamespaceManager xmlnm = new XmlNamespaceManager(xmlDocument.NameTable);
            xmlnm.AddNamespace("ns", "http://www.w3.org/2005/Atom");

            ParseXML(xmlDocument, xmlnm);

            Console.WriteLine("\n---XML parsed---");
            Console.ReadKey();
        }

        public static void ParseXML(XmlDocument xmlFile, XmlNamespaceManager xmlnm)
        {
            XmlNodeList nodes = xmlFile.SelectNodes("//ns:updated | //ns:expires | //ns:title | //ns:summary | //ns:state", xmlnm);

            foreach (XmlNode node in nodes)
            {
                Console.WriteLine(node.Name + " = " + node.InnerXml);
            }
        }
    }
}

// in XPath expression means, you want to select all nodes with specific name, no matter where they are.

If you want to search only <entry></entry> elements, you can use following:
"//ns:entry/ns:updated | //ns:entry/ns:expires | //ns:entry/ns:title | //ns:entry/ns:summary | //ns:entry/ns:state"

Solution 2

I believe the easiest way to parse the XML directly is using LINQ-TO-XML. You can find more info here.

11,671

Author by

user1011394

Updated on June 04, 2022

Comments

user1011394 almost 2 years

I've a problem to parse my XML File (RSS Feed) in C#. I just want to read out the "entry" entries (the root parent - "feed" - is not relevant). All "entry" entries are almost even, except the part "state". Some entries doesn't have that entry.

So i just want to read out the following: "entry" nodes:

updated
expires
title
summary
state (if exists)

Any suggestions? Thank you very much.

<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
   <updated>2011-01-01T00:00:00+0100</updated>
   <link href="http://www.domain.com" rel="self"/>
   <author>
      <name>Mr X</name>
      <email>[email protected]</email>
   </author>
   <title>Some infos....</title>
   <id>domain.com</id>
<entry>
   <updated>2011-01-01T00:00:00Z</updated>
   <expires>2011-01-02T00:00:00Z</expires>
   <title>My first Title</title>
   <id>First ID</id>
  <link type="text/html" rel="alternate"
        href="http://domain.com/firstElement"></link>
   <summary>My first important summary</summary>
   <rights>domain.com</rights>
   <content type="xhtml">
      <div xmlns="http://www.w3.org/1999/xhtml">
         <div>
            <img alt="second" width="32"
                 src="http://domain.com/firstElement.png"/>
         </div>
      </div>
   </content>
</entry>
<entry>
  <updated>2011-01-01T00:00:00Z</updated>
  <expires>2011-01-02T00:00:00Z</expires>
  <title>My second Title</title>
  <state>active</state>
  <id>Second ID</id>
  <link type="text/html" rel="alternate"
        href="http://domain.com/secondElement"></link>
  <summary>My second important summary</summary>
  <rights>domain.com</rights>
  <content type="xhtml">
    <div xmlns="http://www.w3.org/1999/xhtml">
      <div>
        <img alt="second" width="32"
              src="http://domain.com/secondElement.png"/>
      </div>
    </div>
  </content>
  </entry>
</feed>{<?xml version="1.0" encoding="utf-8"?>
<feed xmlns="http://www.w3.org/2005/Atom">
   <updated>2011-01-01T00:00:00+0100</updated>
   <link href="http://www.domain.com" rel="self"/>
   <author>
      <name>Mr X</name>
      <email>[email protected]</email>
   </author>
   <title>Some infos....</title>
   <id>domain.com</id>
<entry>
   <updated>2011-01-01T00:00:00Z</updated>
   <expires>2011-01-02T00:00:00Z</expires>
   <title>My first Title</title>
   <id>First ID</id>
  <link type="text/html" rel="alternate"
        href="http://domain.com/firstElement"></link>
   <summary>My first important summary</summary>
   <rights>domain.com</rights>
   <content type="xhtml">
      <div xmlns="http://www.w3.org/1999/xhtml">
         <div>
            <img alt="second" width="32"
                 src="http://domain.com/firstElement.png"/>
         </div>
      </div>
   </content>
</entry>
<entry>
  <updated>2011-01-01T00:00:00Z</updated>
  <expires>2011-01-02T00:00:00Z</expires>
  <title>My second Title</title>
  <state>active</state>
  <id>Second ID</id>
  <link type="text/html" rel="alternate"
        href="http://domain.com/secondElement"></link>
  <summary>My second important summary</summary>
  <rights>domain.com</rights>
  <content type="xhtml">
    <div xmlns="http://www.w3.org/1999/xhtml">
      <div>
        <img alt="second" width="32"
              src="http://domain.com/secondElement.png"/>
      </div>
    </div>
  </content>
  </entry>
</feed>

My current C# code:

public void ParseXML(XmlDocument xmlFile)
    {
        ArrayList updated = new ArrayList();
        ArrayList expires = new ArrayList();
        ArrayList title = new ArrayList();
        ArrayList summary = new ArrayList();
        ArrayList state = new ArrayList();

        ObservableCollection<TrafficInformation> trafInfo = new ObservableCollection<TrafficInformation>();
        myCollection = trafInfo;
        XmlNodeReader reader = new XmlNodeReader(xmlFile);

        StringBuilder output = new StringBuilder();

        while (reader.Read())
        {
            switch (reader.NodeType)
            {
                case XmlNodeType.Element:
                    if(reader.Name == "updated")
                    {
                        updated.Add(reader.ReadString());
                    }

                    if (reader.Name == "expires")
                    {
                        expires.Add(reader.ReadString());
                    }

                    if (reader.Name == "title")
                    {
                        title.Add(reader.ReadString());
                    }

                    if (reader.Name == "summary")
                    {
                        summary.Add(reader.ReadString());
                    }

                    if (reader.Name == "state")
                    {
                        state.Add(reader.ReadString());
                    }

                    break;
            }
        }
    }

In that case, I don't have a relationship between the data (if state doesn't exists).

Oded over 12 years

What have you tried? Where are you having difficulties? What version of .NET are you using?
user1011394 over 12 years

I'm using .net 4.0. How can I post a formatted code segment in a comment?
Oded over 12 years

Don't post formatted code in comments - instead, edit your question and add detail to it.
Oded over 12 years

Please don't use ArrayList - use List<string> instead. That way, you at least have type safety.
user1011394 over 12 years

Mh ok, I'm going to remember this^^.