Use XpathNavigator to navigate and edit XML data

Introduction

Background

- ASP.NET, C# Medium Knowledge.

- XML and XPATH Knowledge.

Using the code

This article demonstrates how to read data from a XML File, using XPATH. So, let the words aside and go to work.

This is the XML Source:

      
<?xml version="1.0" encoding="utf-8" ?>
<Roles>
<Role name="Admin">
<Username><![CDATA[hGUC0QB2G3l1cb0YSnJkUJpcQB2cv6h3]]></Username>
<Password><![CDATA[P3W+pDC2Vn/TH1Bbgmm/1A==]]></Password>
</Role>
</Roles>

 
//Next, this is the method to get values from XML file:

private MyCredential[] GetAdminCredentials()
{
HttpServerUtility server = HttpContext.Current.Server;
List<MyCredential> credentials = new List<MyCredential>();
try
{
XmlDocument xmlDocument = new XmlDocument();
string filename = @".\Roles.xml";
xmlDocument.Load(server.MapPath(filename));
XPathNavigator nav = xmlDocument.CreateNavigator();
XPathNodeIterator iterator = nav.Select("Roles/Role[@name='Admin']"); //this is a condition. Only nodes which contains role name = 'admin' are processed.
while (iterator.MoveNext()) //while there are nodes where role name='admin'
{
MyCredential credential = new MyCredential();
iterator.Current.MoveToChild("Username",string.Empty);
credential.Username = CryptographyServices.Decrypt(iterator.Current.Value);
iterator.Current.MoveToParent(); //move to root
iterator.Current.MoveToChild("Password", string.Empty);
credential.Password = CryptographyServices.Decrypt(iterator.Current.Value);
credentials.Add(credential);
iterator.Current.MoveToParent(); //move to root again
}
return credentials.ToArray();
}
catch (Exception innerException)
{
throw innerException;
}

}

Points of Interest

In next article we will update a xml file using CData Sections. Thanks for your attention.

History

Keep a running update of any changes or improvements you've made here.