XPATH With Default Namespace In C# – XPathNavigator

This article explains the sample C# code with XPathNavigator to select an XML element from an XML file which is having a default namespace.
Consider the sample XML file with namespace(xmlns) defined ,

   
<!--?xml version="1.0" encoding="UTF-8"?--> 
<country xmlns="http://www.countrys.org/2013/5/Country" version="1.2">
   <state name="Maharashtra"> 
         <city>Pune</city> 
         <city>Mumbai </city> 
   </state>   

  <state name="Maharashtra"> 
         <city>Bangalore</city> 
         <city>Mangalore </city> 
   </state> 
</country>

See the console application sample given below which selects all the City Elements of the State which is having Name attribute value ‘Karnataka’.XPathNavigator is used for parsing.

class Program
{
     static void Main(string[] args)
     {

        //Replace the hardcoded XML  file path with your XML file path.
        XPathDocument xpathDocument = new XPathDocument(@"E:\XmlSamples\Country.xml");
        XPathNavigator navigator = xpathDocument.CreateNavigator();

        //Define the Namespace manager
        XmlNamespaceManager nsmgr = new XmlNamespaceManager(new NameTable());
        nsmgr.AddNamespace("ns", "http://www.countrys.org/2013/13/CountrySchema");

        //Set the Xpath expression
        string xPathQuery = "//ns:State[@Name='Karnataka']/ns:City";
        XPathNodeIterator nodes = navigator.Select(xPathQuery, nsmgr);
        foreach (XPathNavigator item in nodes)
        {
             Console.WriteLine(item.InnerXML);
        }
        Console.Read();
    }
}

Since the XML is having a namespace defined in it, your XPath expression need namespace manager which is defined with the 2 lines below.This namespace manager is used in XpathNavigator select.

XmlNamespaceManager nsmgr = new XmlNamespaceManager(new NameTable());
nsmgr.AddNamespace("ns", "http://www.countrys.org/2013/13/CountrySchema");

Notice the XPath expression  //ns:State[@Name=’Karnataka’]/ns:City, here the text ns:(instead of ns, use any variable name as you like) before every element name is needed since the XML file is having a default namespace. Every node name in the expression needs this namespace text.