Select nodes attribute in XML file using C#

Question

In the following XML file, i try to save in a list all the id attributes:

<?xml version="1.0"?>
<PressReleases>
  <PressRelease id="545" version="1">
    <Name>Convert number to string</Name>
    <Date>20/05/1985</Date>
    <Input>1</Input>
    <Output>One</Output>
  </PressRelease>
  <PressRelease id="544" version="1">
    <Name>Find succeeding characters</Name>
    <Date>19/05/1985</Date>
    <Input>abc</Input>
    <Output>def</Output>
  </PressRelease>
  <PressRelease id="543" version="1">
    <Name>Convert multiple numbers to strings</Name>
    <Date>17/05/1985</Date>
    <Input>123</Input>
    <Output>One Two Three</Output>
  </PressRelease>
  <PressRelease id="542" version="1">
    <Name>Find correlated key</Name>
    <Date>02/05/1985</Date>
    <Input>a1</Input>
    <Output>b1</Output>
  </PressRelease>
  <PressRelease id="541" version="1">
    <Name>Count characters</Name>
    <Date>04/02/1985</Date>
    <Input>This is a test</Input>
    <Output>14</Output>
  </PressRelease>
  <PressRelease id="540" version="1">
    <Name>Another Test</Name>
    <Date>09/01/1985</Date>
    <Input>Test Input</Input>
    <Output>10</Output>
  </PressRelease>
</PressReleases>

This block of code saves only the first Id written in the first Press Release node (545). I need all of them (545,544 ect)

    XmlDocument doc = new XmlDocument();
    doc.Load(@"C:\Users\ARNAUDR\Desktop\test.xml");
    //string xmlcontents = doc.InnerXml;

    XmlNodeList xnList = doc.SelectNodes("/PressReleases");
    List<int> IDsInDistantXML = new List<int>();
    foreach (XmlNode xn in xnList)
    {
        XmlNode PressRelease = xn.SelectSingleNode("PressRelease");
        if (PressRelease != null)
        {
            IDsInDistantXML.Add(Convert.ToInt16(PressRelease.Attributes["id"].Value));
        }
    }

Thanks in advance for your help

Sergey Berezovskiy · Accepted Answer · 2014-02-12 10:15:53Z

2

I suggest you to use Linq to Xml:

XDocument xdoc = XDocument.Load(@"C:\Users\ARNAUDR\Desktop\test.xml");
List<int> ids = xdoc.Root.Elements("PressRelease")
                    .Select(pr => (int)pr.Attribute("id"))
                    .ToList();

Note: your problem is that you always select first (single node) PressRelease node from root, and you are enumerating root nodes (which is always one) instead of enumerating PressRelease nodes. Here is fixed solution:

XmlNodeList pressReleases = doc.SelectNodes("/PressReleases/PressRelease");
List<int> IDsInDistantXML = new List<int>();
foreach (XmlNode pr in pressReleases)    
    IDsInDistantXML.Add(Convert.ToInt32(pr.Attributes["id"].Value));

edited Feb 12, 2014 at 10:15

answered Feb 12, 2014 at 10:09

Sergey Berezovskiy

237k44 gold badges441 silver badges468 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Dirk Over a year ago

+1 for actually pointing out the problem. If he'd adjust the first XPath expresion to /PressReleases/PressRelease and then iterate over the results he can achieve the same. But using LINQ to XML is more elegant.

Sergey Berezovskiy Over a year ago

@Dirk thanks :) Already was posting fixed solution with correct XPath selector

StuartLC · Accepted Answer · 2014-02-12 10:13:53Z

1

Alternatively, if all you need is the one attribute, change your SelectNodes xpath directly to the nodes:

List<int> IDsInDistantXML = new List<int>();
foreach (var xn in doc.SelectNodes("/PressReleases/PressRelease"))
{
    IDsInDistantXML.Add(Convert.ToInt16(xn.Attributes["id"].Value));
}

answered Feb 12, 2014 at 10:13

StuartLC

108k18 gold badges225 silver badges295 bronze badges

Collectives™ on Stack Overflow

Select nodes attribute in XML file using C#

2 Answers 2

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related