XDocument or XElement with XmlNamespace

Loading or parsing xml with namspaces are common in development scenarios.When we work with Xdocument and XElement there is no direct way to pass the namespace. Let see how we can work with namspace.

Step1 Create a NameTable

NameTable nameTable = new NameTable();

Step2 Create Namespace Manager

XmlNamespaceManager nameSpaceManager = new XmlNamespaceManager(nameTable );

Step3 Add the Namespace or Ignore It

Adding
nameSpaceManager.AddNamespace("p", "office.server.policy");
Ignoring
nameSpaceManager.AddNamespace("log4net", "urn:ignore");

Step4 Create a ParserContext

XmlParserContext parserContext = new XmlParserContext(null, nameSpaceManager,
null, XmlSpace.None);

Step5 Create a XmlTextReader

XmlTextReader txtReader = new XmlTextReader("Strin XML", XmlNodeType.Element,
parserContext);

Step6 Load the XML

XElement elem = XElement.Load(txtReader);

For Example we have a Log4net xml and we need to parse it

<log4net:event logger="TestingTransmitter.Program"
timestamp="2009-08-02T17:50:18.928+01:00"
level="ERROR"
thread="9"
domain="TestingTransmitter.vshost.exe"
username="domain\user">
<log4net:message>Log entry 103</log4net:message>
<log4net:properties>
<log4net:data name="log4net:HostName" value="machine" />
</log4net:properties>
</log4net:event>

Following code will load the xml without error like "an undeclared namespace"

NameTable nameTable = new NameTable();
XmlNamespaceManager nameSpaceManager
= new XmlNamespaceManager(nameTable );
nameSpaceManager.AddNamespace("log4net", "urn:ignore");
XmlParserContext
parserContext = new XmlParserContext(null, nameSpaceManager,
null,
XmlSpace.None);
XmlTextReader txtReader = new XmlTextReader("Strin XML",
XmlNodeType.Element,
parserContext );
XElement elem =
XElement.Load(txtReader);

Loading xml from string

XML Document Approach

Let see how we can load xml from a string to a xmldocument
object
Step 1 Create XmlDocument Object

XmlDocument doc = new
XmlDocument();

Step 2
Creat a StringReader Object

System.IO.StringReader sr = new
System.IO.StringReader("XML
Sring");

Step 3 Create
XmlReader Object

XmlReader xmlrd =
XmlReader.Create(sr)

Here we are calling XmlReader.Create method and passing a
StringReader object
Step 4 Load xml

doc.Load(xmlrd);

Uses Load method of
XmlDocument object and pass XmlReader

XDocument Approach

XDocument.Parse("StringXML", LoadOptions.PreserveWhitespace);
In Xdocument you can directly pass the string and specify the load
options.Even you can directly parse into a XElement
XElement.Parse("StringXML")
You could also specify the declaration for your xml when you are creating the XDocument.Look at the following line
XDocument xdoc = new XDocument(new XDeclaration("1.0", "ISO-8859-1", "YES"), XElement.Parse("StringXML"));

Here XDeclaration you can specify version of xml,encoding you are using and standalone or not