How can we Specify Namespaces in XPath Queries without hard coding

When using XPath in .NET (via a navigator or SelectNodes/SelectSingleNode) on XML with namespaces you need to:

     Provide your own XmlNamespaceManager and explicitly prefix all elements in XPath expression, which are in namespace.

Please find the below sample:

XPathDocument xdoc = new XPathDocument(string.Format(@"{0}\SubmiOrderReq1.xml",Environment.CurrentDirectory));

XPathNavigator nav = xdoc.CreateNavigator();

XPathNodeIterator nodes = (XPathNodeIterator)nav.Evaluate("//namespace::*");

XmlNamespaceManager ns = new XmlNamespaceManager(new NameTable());

//Gets the name spaces from xml.

XmlDocument doc = new XmlDocument();

doc.Load(string.Format(@"{0}\[filename].xml", Environment.CurrentDirectory));

var namespaces = (from XmlNode n in doc.SelectNodes("//*|@*")

     where n.NamespaceURI != string.Empty

     select new

     {

          Prefix = n.Prefix,

          Namespace = n.NamespaceURI

     }).Distinct();

int count = 0;

foreach (var item in namespaces)

{

    ns.AddNamespace("ns" + count.ToString(), item.Namespace);

    count++;

}

Console.WriteLine("Payment type - CreditCard" + nav.Evaluate("count(//ns2:PaymentDetails[ns3:PaymentType = \"CreditCard\"])",ns));   //To get the CreditCard payment type PaymentDetails.

Console.WriteLine(nav.Evaluate("count(//ns2:ProductDetails)", ns));    //To get the ProductDetails count

Console.ReadLine();

The sample xml message structure looks like below

<RootNode>

     <Record>

          <PaymentDetails>

               <PaymentType> cash <PaymentType>

          <PaymentDetails>

          <PaymentDetails>

               <PaymentType> CreditCard <PaymentType>

          <PaymentDetails>

     </Record>

</RootNode>