Question

I’m trying to use XmlDocument() to read an XML file node by node an output each element.

After much trial-and-error, I determined that having an xmlns attribute on my node causes no nodes to be returned from SelectNodes() call. Not sure why.

Since I can’t change the output format and don’t have access to the actual namespace, what are my options to get around this issue?

In addition, I have some elements that have subnodes. How do I access these while looping through the XML file? I.E., I need to decrypt the CipherValue elements, but not sure how to access this node anyway?

Sample below:

doc.Load(@"test.xml");
XmlNodeList logEntryNodeList = doc.SelectNodes("/Logs/LogEntry");
Console.WriteLine("Nodes = {0}", logEntryNodeList.Count);
foreach (XmlNode xn in logEntryNodeList)
{
    string dateTime = xn["DateTime"].InnerText;
    string sequence = xn["Sequence"].InnerText;
    string appId = xn["AppID"].InnerText;
    Console.WriteLine("{0}    {1} {2}", dateTime, sequence, appId);
}

Sample XML looks like this:

<Logs>
<LogEntry Version="1.5" PackageVersion="10.10.0.10" xmlns="http://private.com">
  <DateTime>2013-02-04T14:05:42.912349-06:00</DateTime>
  <Sequence>5058</Sequence>
  <AppID>TEST123</AppID>
  <StatusDesc>
    <EncryptedData>
      <CipherData xmlns="http://www.w3.org/2001/04/xmlenc#">
        <CipherValue>---ENCRYPTED DATA BASE64---</CipherValue>
      </CipherData>
    </EncryptedData>
  </StatusDesc>
  <Severity>Detail</Severity>
</LogEntry>
<LogEntry Version="1.5" PackageVersion="10.10.0.10" xmlns="http://private.com">
  <DateTime>2013-02-04T14:05:42.912350-06:00</DateTime>
  <Sequence>5059</Sequence>
  <AppID>TEST123</AppID>
  <StatusDesc>
    <EncryptedData>
      <CipherData xmlns="http://www.w3.org/2001/04/xmlenc#">
        <CipherValue>---ENCRYPTED DATA BASE64---</CipherValue>
      </CipherData>
    </EncryptedData>
  </StatusDesc>
  <Severity>Detail</Severity>
</LogEntry>
</Logs>

Answer 1

You can use Linq to Xml (as Jon stated). Here is code which parses your xml file with respect to namespaces. Result is a strongly typed sequence of anonymous objects (i.e. Date property has type of DateTime, Sequence is integer, and AppID is a string):

XDocument xdoc = XDocument.Load("test.xml");
XNamespace ns = "http://private.com";
var entries = xdoc.Descendants("Logs")
                  .Elements(ns + "LogEntry")
                  .Select(e => new {
                      Date = (DateTime)e.Element(ns + "DateTime"),
                      Sequence = (int)e.Element(ns + "Sequence"),
                      AppID = (string)e.Element(ns + "AppID")
                  }).ToList();   

Console.WriteLine("Entries count = {0}", entries.Count);    

foreach (var entry in entries)
{
    Console.WriteLine("{0}\t{1} {2}", 
                      entry.Date, entry.Sequence, entry.AppID);
}