Question

  <?xml version="1.0"?>
     <configuration  xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
         <configSections>

I have a web.config file which contains xmlns in configuration tag.

I want to delete a specific node. but I am not able to read this file.

Below is the code :

XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.Load(PATH + WEB_CONFIG_PATH);
        //XmlNode t = xmlDoc.SelectSingleNode("/system.webServer/handlers  /add[@path='Reserved.ReportViewerWebControl.axd']");
        XmlNode t = xmlDoc.SelectSingleNode("/configuration/system.webServer");
        if (t != null)
        {
            t.ParentNode.RemoveChild(t);
            xmlDoc.Save(PATH + WEB_CONFIG_PATH);
        }

If I remove xmlns from configuration tag this code works fine.

please provide some solution so that this code can work if xmlns is present.

Answer 1

You need to add support for the XML namespace by adding a XmlNamespaceManager to your code, and using it on the SelectSingleNode call. Also, you need to tweak the XPath for your call to include XML namespace prefixes:

XmlDocument xmlDoc = new XmlDocument();
xmlDoc.Load(PATH + WEB_CONFIG_PATH);

// add a XmlNamespaceManager to deal with the XML namespaces in your XML document        
XmlNamespaceManager xmlNsMgr = new XmlNamespaceManager(xmlDoc.NameTable);

// add an explicit XML namespace with prefix. NOTE: for some reason, the approach of using
// an empty string indicating a *default* XML namespace doesn't work with .NET's XmlDocument
xmlNsMgr.AddNamespace("ns", "http://schemas.microsoft.com/.NetConfiguration/v2.0");

// tweak your call - use the XML namespace prefix in your XPath, provide the namespace manager
XmlNode t = xmlDoc.SelectSingleNode("/ns:configuration/ns:system.webServer", xmlNsMgr);

if (t != null)
{
    ......