System.Xml.XmlNodeReader Class

Summary

Represents a reader that provides fast, non-cached forward only access to XML data in an XmlNode.

C# Syntax:

public class XmlNodeReader : XmlReader

The XmlNodeReader has the ability to read an XML DOM subtree. This class does not support DTD or schema validation. To perform data validation, use the XmlValidatingReader.

To read strongly typed data, use the XmlConvert class. For example, the following C# code reads in data and converts it from a String to a Double.

          Double price = XmlConvert.ToDouble(reader.Value);
        

For further discussion on the XmlReader classes, see the conceptual topic at MSDN: readingxmlwithxmlreader.

System.Xml Namespace

System.Xml.XmlNodeReader Member List:

Public Constructors

ctor #1

Creates an instance of the XmlNodeReader class using the specified XmlNode.

Public Properties

AttributeCount	Read-only Overridden: Gets the number of attributes on the current node.
BaseURI	Read-only Overridden: Gets the base URI of the current node.
CanResolveEntity	Read-only Overridden: Gets a value indicating whether this reader can parse and resolve entities.
Depth	Read-only Overridden: Gets the depth of the current node in the XML document.
EOF	Read-only Overridden: Gets a value indicating whether the reader is positioned at the end of the stream.
HasAttributes	Read-only Overridden: Gets a value indicating whether the current node has any attributes.
HasValue	Read-only Overridden: Gets a value indicating whether the current node can have a XmlNodeReader.Value.
IsDefault	Read-only Overridden: Gets a value indicating whether the current node is an attribute that was generated from the default value defined in the DTD or schema.
IsEmptyElement	Read-only Overridden: Gets a value indicating whether the current node is an empty element (for example, <MyElement/> ).
Item	Read-only Overloaded: Item[int i] {get Overridden: Gets the value of the attribute with the specified index.
Item	Read-only Overloaded: Item[string name] {get Overridden: Gets the value of the attribute with the specified name.
Item	Read-only Overloaded: Item[string name, string namespaceURI] {get Overridden: Gets the value of the attribute with the specified local name and namespace URI.
LocalName	Read-only Overridden: Gets the local name of the current node.
Name	Read-only Overridden: Gets the qualified name of the current node.
NamespaceURI	Read-only Overridden: Gets the namespace URI (as defined in the W3C Namespace specification) of the node on which the reader is positioned.
NameTable	Read-only Overridden: Gets the XmlNameTable associated with this implementation.
NodeType	Read-only Overridden: Gets the type of the current node.
Prefix	Read-only Overridden: Gets the namespace prefix associated with the current node.
QuoteChar	Read-only Overridden: Gets the quotation mark character used to enclose the value of an attribute node.
ReadState	Read-only Overridden: Gets the state of the reader.
Value	Read-only Overridden: Gets the text value of the current node.
XmlLang	Read-only Overridden: Gets the current xml:lang scope.
XmlSpace	Read-only Overridden: Gets the current xml:space scope.

Public Methods

Close	Overridden: Changes the XmlNodeReader.ReadState to Closed.
Equals (inherited from System.Object)	See base class member description: System.Object.Equals Derived from System.Object, the primary base class for all objects.
GetAttribute	Overloaded: GetAttribute(int attributeIndex) Overridden: Gets the value of the attribute with the specified index.
GetAttribute	Overloaded: GetAttribute(string name) Overridden: Gets the value of the attribute with the specified name.
GetAttribute	Overloaded: GetAttribute(string name, string namespaceURI) Overridden: Gets the value of the attribute with the specified local name and namespace URI.
GetHashCode (inherited from System.Object)	See base class member description: System.Object.GetHashCode Derived from System.Object, the primary base class for all objects.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
IsStartElement (inherited from System.Xml.XmlReader)	Overloaded: IsStartElement() See base class member description: System.Xml.XmlReader.IsStartElement Calls XmlReader.MoveToContent and tests if the current content node is a start tag or empty element tag.
IsStartElement (inherited from System.Xml.XmlReader)	Overloaded: IsStartElement(string name) See base class member description: System.Xml.XmlReader.IsStartElement Calls XmlReader.MoveToContent and tests if the current content node is a start tag or empty element tag and if the XmlReader.Name property of the element found matches the given argument.
IsStartElement (inherited from System.Xml.XmlReader)	Overloaded: IsStartElement(string localname, string ns) See base class member description: System.Xml.XmlReader.IsStartElement Calls XmlReader.MoveToContent and tests if the current content node is a start tag or empty element tag and if the XmlReader.LocalName and XmlReader.NamespaceURI properties of the element found match the given strings.
LookupNamespace	Overridden: Resolves a namespace prefix in the current element's scope.
MoveToAttribute	Overloaded: MoveToAttribute(int attributeIndex) Overridden: Moves to the attribute with the specified index.
MoveToAttribute	Overloaded: MoveToAttribute(string name) Overridden: Moves to the attribute with the specified name.
MoveToAttribute	Overloaded: MoveToAttribute(string name, string namespaceURI) Overridden: Moves to the attribute with the specified local name and namespace URI.
MoveToContent (inherited from System.Xml.XmlReader)	See base class member description: System.Xml.XmlReader.MoveToContent Checks whether the current node is a content (non-white space text, CDATA, Element, EndElement, EntityReference, or EndEntity) node. If the node is not a content node, the reader skips ahead to the next content node or end of file. It skips over nodes of the following type: ProcessingInstruction, DocumentType, Comment, Whitespace, or SignificantWhitespace.
MoveToElement	Overridden: Moves to the element that contains the current attribute node.
MoveToFirstAttribute	Overridden: Moves to the first attribute.
MoveToNextAttribute	Overridden: Moves to the next attribute.
Read	Overridden: Reads the next node from the stream.
ReadAttributeValue	Overridden: Parses the attribute value into one or more Text, EntityReference, or EndEntity nodes.
ReadElementString (inherited from System.Xml.XmlReader)	Overloaded: ReadElementString() See base class member description: System.Xml.XmlReader.ReadElementString Reads a text-only element.
ReadElementString (inherited from System.Xml.XmlReader)	Overloaded: ReadElementString(string name) See base class member description: System.Xml.XmlReader.ReadElementString Checks that the XmlReader.Name property of the element found matches the given string before reading a text-only element.
ReadElementString (inherited from System.Xml.XmlReader)	Overloaded: ReadElementString(string localname, string ns) See base class member description: System.Xml.XmlReader.ReadElementString Checks that the XmlReader.LocalName and XmlReader.NamespaceURI properties of the element found matches the given strings before reading a text-only element.
ReadEndElement (inherited from System.Xml.XmlReader)	See base class member description: System.Xml.XmlReader.ReadEndElement Checks that the current content node is an end tag and advances the reader to the next node.
ReadInnerXml	Overridden: Reads all the content, including markup, as a string.
ReadOuterXml	Overridden: Reads the content, including markup, representing this node and all its children.
ReadStartElement (inherited from System.Xml.XmlReader)	Overloaded: ReadStartElement() See base class member description: System.Xml.XmlReader.ReadStartElement Checks that the current node is an element and advances the reader to the next node.
ReadStartElement (inherited from System.Xml.XmlReader)	Overloaded: ReadStartElement(string name) See base class member description: System.Xml.XmlReader.ReadStartElement Checks that the current content node is an element with the given XmlReader.Name and advances the reader to the next node.
ReadStartElement (inherited from System.Xml.XmlReader)	Overloaded: ReadStartElement(string localname, string ns) See base class member description: System.Xml.XmlReader.ReadStartElement Checks that the current content node is an element with the given XmlReader.LocalName and XmlReader.NamespaceURI and advances the reader to the next node.
ReadString	Overridden: Reads the contents of an element or text node as a string.
ResolveEntity	Overridden: Resolves the entity reference for EntityReference nodes.
Skip	Overridden: Skips the children of the current node.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.

Protected Methods

Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.

Hierarchy:

• System.Object
• System.Xml.XmlReader
• System.Xml.XmlNodeReader

System.Xml.XmlNodeReader Member Details

Summary

Creates an instance of the XmlNodeReader class using the specified XmlNode.

C# Syntax:

public XmlNodeReader(    XmlNode node );

node

The XmlNode you want to read.

The following C# code creates an XmlNodeReader.

              XmlDocument doc = new XmlDocument();
              doc.Load("sample.xml");
              XmlNodeReader reader = new XmlNodeReader(doc);
            

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Summary

Gets the number of attributes on the current node.

C# Syntax:

public override int AttributeCount {get;}

This property is relevant to Element, DocumentType and XmlDeclaration nodes only. (Other node types do not have attributes.)

The following example reads all the attributes on the root node.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the attributes on the root element.
       reader.MoveToContent();
       if (reader.HasAttributes){
         for (int i=0; i<reader.AttributeCount; i++){
            reader.MoveToAttribute(i);
            Console.WriteLine("{0} = {1}", reader.Name, reader.Value);
         }
         //Return the reader to the book element.
         reader.MoveToElement();
       }

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the base URI of the current node.

C# Syntax:

public override string BaseURI {get;}

A networked XML document is comprised of chunks of data aggregated using various W3C standard inclusion mechanisms and therefore contains nodes that come from different places. DTD entities are an example of this, but this is not limited to DTDs. The base URI tells you where these nodes came from. If there is no base URI for the nodes being returned (for example, they were parsed from an in-memory string), String.Empty is returned.

The following example parses a file and displays the base URI of each of the nodes.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create and load an XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load("http://localhost/uri.xml");

        reader = new XmlNodeReader(doc);

        //Parse the file and display the base URI for each node.
        while (reader.Read())
        {
            Console.WriteLine("({0}) {1}", reader.NodeType, reader.BaseURI);
         }           
     }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

The example uses the file, uri.xml, as input. The style.xml file contains the XML text <style>hardcover</style> .

<!-- XML fragment -->
<!DOCTYPE book [<!ENTITY s SYSTEM "tmp/style.xml">]>
<book genre="novel">
  <title>Pride And Prejudice</title>
  <misc>&s;</misc>
</book>

    

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Summary

Gets a value indicating whether this reader can parse and resolve entities.

C# Syntax:

public override bool CanResolveEntity {get;}

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Summary

Gets the depth of the current node in the XML document.

C# Syntax:

public override int Depth {get;}

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Summary

Gets a value indicating whether the reader is positioned at the end of the stream.

C# Syntax:

public override bool EOF {get;}

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Summary

Gets a value indicating whether the current node has any attributes.

C# Syntax:

public override bool HasAttributes {get;}

The following example reads all the attributes on the root node.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the attributes on the root element.
       reader.MoveToContent();
       if (reader.HasAttributes){
         for (int i=0; i<reader.AttributeCount; i++){
            reader.MoveToAttribute(i);
            Console.WriteLine("{0} = {1}", reader.Name, reader.Value);
         }
         //Return the reader to the book element.
         reader.MoveToElement();
       }

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets a value indicating whether the current node can have a XmlNodeReader.Value.

C# Syntax:

public override bool HasValue {get;}

The following table lists node types that have a value to return.

Node Type	Value
Attribute	The value of the attribute.
CDATA	The content of the CDATA section.
Comment	The content of the comment.
DocumentType	The internal subset.
ProcessingInstruction	The entire content, excluding the target.
SignificantWhitespace	The white space between markup in a mixed content model.
Text	The content of the text node.
Whitespace	The white space between markup.
XmlDeclaration	The content of the declaration.

The following example displays the value for every node which can have a value.

using System;
using System.IO;
using System.Xml;

public class Sample
{

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create and load an XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.LoadXml("<?xml version='1.0' ?>" +
                    "<!DOCTYPE book [<!ENTITY h 'hardcover'>]>" +
                    "<book>" +
                    "<title>Pride And Prejudice</title>" +
                    "<misc>&h;</misc>" +
                    "</book>");

        reader = new XmlNodeReader(doc);

        //Parse the file and display each node.
        while (reader.Read())
        {
           if (reader.HasValue)
             Console.WriteLine("({0})  {1}={2}", reader.NodeType, reader.Name, reader.Value);
           else
             Console.WriteLine("({0}) {1}", reader.NodeType, reader.Name);
         }           
     }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

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Summary

Gets a value indicating whether the current node is an attribute that was generated from the default value defined in the DTD or schema.

C# Syntax:

public override bool IsDefault {get;}

This property applies to attribute nodes only. If the reader is not positioned on an attribute node, this property returns false.

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Summary

Gets a value indicating whether the current node is an empty element (for example, <MyElement/> ).

C# Syntax:

public override bool IsEmptyElement {get;}

This property enables you to determine the difference between the following:

<item bar="123"/> (IsEmptyElement is true).

<item bar="123"> (IsEmptyElement is false).

A corresponding EndElement node is not generated for empty elements.

The following example displays the text content of each element.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book>" +
                   "<title>Pride And Prejudice</title>" +
                   "<price>19.95</price>" +
                   "<misc/>" +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Parse the XML and display the text content of each of the elements.
       while (reader.Read()){
         if (reader.IsStartElement()){
           if (reader.IsEmptyElement)
              Console.WriteLine("<{0}/>", reader.Name);
           else{
               Console.Write("<{0}> ", reader.Name);
               reader.Read(); //Read the start tag.
               if (reader.IsStartElement())  //Handle nested elements.
                   Console.Write("\r\n<{0}>", reader.Name);
               Console.WriteLine(reader.ReadString());  //Read the text content of the element.
           }
         }
       } 
       
     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the value of the attribute with the specified index.

C# Syntax:

public override string this[int i] {get;}

i

The index of the attribute.

Exceptions

Exception Type	Condition
ArgumentOutOfRangeException	The i parameter is less than 0 or greater than or equal to XmlNodeReader.AttributeCount.

This property does not move the reader.

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Summary

Gets the value of the attribute with the specified name.

C# Syntax:

public override string this[string name] {get;}

name

The qualified name of the attribute.

This property does not move the reader. If the reader is positioned on a DocumentType node, this method can be used to get the PUBLIC and SYSTEM literals, for example, reader["PUBLIC"]

The following example gets the value of the ISBN attribute.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       // Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the ISBN attribute.
       reader.MoveToContent();
       string isbn =reader["ISBN"];
       Console.WriteLine("The ISBN value: " + isbn);

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the value of the attribute with the specified local name and namespace URI.

C# Syntax:

public override string this[string name, string namespaceURI] {get;}

name

The local name of the attribute.

namespaceURI

The namespace URI of the attribute.

This property does not move the reader.

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Summary

Gets the local name of the current node.

C# Syntax:

public override string LocalName {get;}

The following example displays the local name of each node, and, if they exist, the prefix and namespace URI.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book xmlns:bk='urn:samples'> " +
                   "<title>Pride And Prejudice</title>" +
                   "<bk:genre>novel</bk:genre>" +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Parse the XML.  If they exist, display the prefix and  
       //namespace URI of each node.
       while (reader.Read()){
         if (reader.IsStartElement()){
           if (reader.Prefix==String.Empty)
              Console.WriteLine("<{0}>", reader.LocalName);
           else{
               Console.Write("<{0}:{1}>", reader.Prefix, reader.LocalName);
               Console.WriteLine(" The namespace URI is " + reader.NamespaceURI);
           }
         }
       }
       
     } 
     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the qualified name of the current node.

C# Syntax:

public override string Name {get;}

The following example reads an XML and displays each of the nodes.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const String filename = "items.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create an XmlNodeReader to read the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load(filename);
        reader = new XmlNodeReader(doc);

        //Parse the file and display each of the nodes.
        while (reader.Read())
        {
           switch (reader.NodeType)
           {
             case XmlNodeType.Element:
               Console.Write("<{0}>", reader.Name);
               break;
             case XmlNodeType.Text:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.CDATA:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.ProcessingInstruction:
               Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
               break;
             case XmlNodeType.Comment:
               Console.Write("<!--{0}-->", reader.Value);
               break;
             case XmlNodeType.XmlDeclaration:
               Console.Write("<?xml version='1.0'?>");
               break;
             case XmlNodeType.Document:
               break;
             case XmlNodeType.EndElement:
               Console.Write("</{0}>", reader.Name);
               break;
           }       
          }           
        }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

The example uses the file, items.xml, as input.

<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>test with a child element <more/> stuff</Item>
  <Item>test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: &#65;</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

    

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Summary

Gets the namespace URI (as defined in the W3C Namespace specification) of the node on which the reader is positioned.

C# Syntax:

public override string NamespaceURI {get;}

This property is relevant to Element and Attribute nodes only.

The following example displays the local name of each node, and, if they exist, the prefix and namespace URI.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book xmlns:bk='urn:samples'> " +
                   "<title>Pride And Prejudice</title>" +
                   "<bk:genre>novel</bk:genre>" +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Parse the XML.  If they exist, display the prefix and  
       //namespace URI of each node.
       while (reader.Read()){
         if (reader.IsStartElement()){
           if (reader.Prefix==String.Empty)
              Console.WriteLine("<{0}>", reader.LocalName);
           else{
               Console.Write("<{0}:{1}>", reader.Prefix, reader.LocalName);
               Console.WriteLine(" The namespace URI is " + reader.NamespaceURI);
           }
         }
       }
       
     } 
     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the XmlNameTable associated with this implementation.

C# Syntax:

public override XmlNameTable NameTable {get;}

All node and attribute names returned from this class are atomized using the NameTable. When the same name is returned multiple times (for example, Customer), then the same String object will be returned for that name. This makes it possible for you to write efficient code that does object comparisons on these strings instead of expensive string comparisons.

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Summary

Gets the type of the current node.

C# Syntax:

public override XmlNodeType NodeType {get;}

The following example reads an XML and displays each of the nodes.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const String filename = "items.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create an XmlNodeReader to read the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load(filename);
        reader = new XmlNodeReader(doc);

        //Parse the file and display each of the nodes.
        while (reader.Read())
        {
           switch (reader.NodeType)
           {
             case XmlNodeType.Element:
               Console.Write("<{0}>", reader.Name);
               break;
             case XmlNodeType.Text:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.CDATA:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.ProcessingInstruction:
               Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
               break;
             case XmlNodeType.Comment:
               Console.Write("<!--{0}-->", reader.Value);
               break;
             case XmlNodeType.XmlDeclaration:
               Console.Write("<?xml version='1.0'?>");
               break;
             case XmlNodeType.Document:
               break;
             case XmlNodeType.EndElement:
               Console.Write("</{0}>", reader.Name);
               break;
           }       
          }           
        }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

The example uses the file, items.xml, as input.

<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>test with a child element <more/> stuff</Item>
  <Item>test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: &#65;</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

    

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Summary

Gets the namespace prefix associated with the current node.

C# Syntax:

public override string Prefix {get;}

The following example displays the local name of each node, and, if they exist, the prefix and namespace URI.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book xmlns:bk='urn:samples'> " +
                   "<title>Pride And Prejudice</title>" +
                   "<bk:genre>novel</bk:genre>" +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Parse the XML.  If they exist, display the prefix and  
       //namespace URI of each node.
       while (reader.Read()){
         if (reader.IsStartElement()){
           if (reader.Prefix==String.Empty)
              Console.WriteLine("<{0}>", reader.LocalName);
           else{
               Console.Write("<{0}:{1}>", reader.Prefix, reader.LocalName);
               Console.WriteLine(" The namespace URI is " + reader.NamespaceURI);
           }
         }
       }
       
     } 
     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the quotation mark character used to enclose the value of an attribute node.

C# Syntax:

public override char QuoteChar {get;}

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Summary

Gets the state of the reader.

C# Syntax:

public override ReadState ReadState {get;}

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Summary

Gets the text value of the current node.

C# Syntax:

public override string Value {get;}

The following example reads an XML and displays each node.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const String filename = "items.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create an XmlNodeReader to read the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load(filename);
        reader = new XmlNodeReader(doc);

        //Parse the file and display each of the nodes.
        while (reader.Read())
        {
           switch (reader.NodeType)
           {
             case XmlNodeType.Element:
               Console.Write("<{0}>", reader.Name);
               break;
             case XmlNodeType.Text:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.CDATA:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.ProcessingInstruction:
               Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
               break;
             case XmlNodeType.Comment:
               Console.Write("<!--{0}-->", reader.Value);
               break;
             case XmlNodeType.XmlDeclaration:
               Console.Write("<?xml version='1.0'?>");
               break;
             case XmlNodeType.Document:
               break;
             case XmlNodeType.EndElement:
               Console.Write("</{0}>", reader.Name);
               break;
           }       
          }           
        }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

The example uses the file, items.xml, as input.

<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>test with a child element <more/> stuff</Item>
  <Item>test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: &#65;</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

    

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Summary

Gets the current xml:lang scope.

C# Syntax:

public override string XmlLang {get;}

This property represents the xml:lang scope within which the current node resides. For example, here is an XML fragment with xml:lang set to US English in the root element:

<root xml:lang="en-us">

<name>Fred</name>

</root>

When the reader is positioned on the name element, you can use this property to find that it is in the scope of a US English xml:lang attribute.

The string returned is also in XmlNodeReader.NameTable.

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Summary

Gets the current xml:space scope.

C# Syntax:

public override XmlSpace XmlSpace {get;}

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Summary

Changes the XmlNodeReader.ReadState to Closed.

C# Syntax:

public override void Close();

This method also releases any resources held while reading. If Close has already been called, no action is performed.

The following example parses a file and closes the reader.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const String filename = "items.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create an XmlNodeReader to read the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load(filename);
        reader = new XmlNodeReader(doc);

        //Parse the file and display each of the nodes.
        while (reader.Read())
        {
           switch (reader.NodeType)
           {
             case XmlNodeType.Element:
               Console.Write("<{0}>", reader.Name);
               break;
             case XmlNodeType.Text:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.CDATA:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.ProcessingInstruction:
               Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
               break;
             case XmlNodeType.Comment:
               Console.Write("<!--{0}-->", reader.Value);
               break;
             case XmlNodeType.XmlDeclaration:
               Console.Write("<?xml version='1.0'?>");
               break;
             case XmlNodeType.Document:
               break;
             case XmlNodeType.EndElement:
               Console.Write("</{0}>", reader.Name);
               break;
           }       
          }           
        }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

The example uses the file, items.xml, as input.

<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>test with a child element <more/> stuff</Item>
  <Item>test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: &#65;</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

    

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Inherited
See base class member description: System.Object.Equals

C# Syntax:

public virtual bool Equals(    object obj );

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.Finalize

C# Syntax:

~XmlNodeReader();

For more information on members inherited from System.Object click on the link above.

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Summary

Gets the value of the attribute with the specified index.

C# Syntax:

public override string GetAttribute(    int attributeIndex );

attributeIndex

The index of the attribute. The index is zero-based. (The first attribute has index 0.)

Return Value:

The value of the specified attribute.

Exceptions

Exception Type	Condition
ArgumentOutOfRangeException	The i parameter is less than 0 or greater than or equal to XmlNodeReader.AttributeCount.

This method does not move the reader.

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Summary

Gets the value of the attribute with the specified name.

C# Syntax:

public override string GetAttribute(    string name );

name

The qualified name of the attribute.

Return Value:

The value of the specified attribute. If the attribute is not found, String.Empty is returned.

This method does not move the reader.

If the reader is positioned on a DocumentType node, this method can be used to get the PUBLIC and SYSTEM literals, for example, reader.GetAttribute("PUBLIC")

The following example gets the value of the ISBN attribute.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       // Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the ISBN attribute.
       reader.MoveToContent();
       string isbn = reader.GetAttribute("ISBN");
       Console.WriteLine("The ISBN value: " + isbn);

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Gets the value of the attribute with the specified local name and namespace URI.

C# Syntax:

public override string GetAttribute(    string name,    string namespaceURI );

name

The local name of the attribute.

namespaceURI

The namespace URI of the attribute.

Return Value:

The value of the specified attribute. If the attribute is not found, String.Empty is returned.

The following XML contains an attribute in a specific namespace:

<test xmlns:dt="urn:datatypes" dt:type="int"/>

You can lookup the dt:type attribute using one argument (prefix and local name) or two arguments (local name and namespace URI):

String dt = reader.GetAttribute("dt:type");

String dt2 = reader.GetAttribute("type","urn:datatypes");

To lookup the xmlns:dt attribute, use one of the following arguments:

String dt3 = reader.GetAttribute("xmlns:dt");

String dt4 = reader.GetAttribute("dt",http://www.w3.org/2000/xmlns/);

You can also get this information using the XmlNodeReader.Prefix property.

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Inherited
See base class member description: System.Object.GetHashCode

C# Syntax:

public virtual int GetHashCode();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.GetType

C# Syntax:

public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Xml.XmlReader.IsStartElement

Summary

Calls XmlReader.MoveToContent and tests if the current content node is a start tag or empty element tag.

C# Syntax:

public virtual bool IsStartElement();

Return Value:

true if MoveToContent finds a start tag or empty element tag; false if a node type other than XmlNodeType.Element was found.

Exceptions

Exception Type	Condition
XmlException	Incorrect XML is encountered in the input stream.

This method skips white space, comments, and processing instructions until the reader is positioned on a content node. The method then tests if the current node is an element.

The following example displays the text content of each element.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlTextReader reader = null;

    try
    {
       //Load the reader with the XML file.
       reader = new XmlTextReader("elems.xml");
  
       //Parse the XML and display the text content of each of the elements.
       while (reader.Read()){
         if (reader.IsStartElement()){
           if (reader.IsEmptyElement)
              Console.WriteLine("<{0}/>", reader.Name);
           else{
               Console.Write("<{0}> ", reader.Name);
               reader.Read(); //Read the start tag.
               if (reader.IsStartElement())  //Handle nested elements.
                 Console.Write("\r\n<{0}>", reader.Name);
               Console.WriteLine(reader.ReadString());  //Read the text content of the element.
           }
         }
       } 
       
     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

The example uses the file, elems.xml, as input.

<book>
  <title>Pride And Prejudice</title>
  <price>19.95</price>
  <misc/>
</book>

    

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Inherited
See base class member description: System.Xml.XmlReader.IsStartElement

Summary

Calls XmlReader.MoveToContent and tests if the current content node is a start tag or empty element tag and if the XmlReader.Name property of the element found matches the given argument.

C# Syntax:

public virtual bool IsStartElement(    string name );

name

The string matched against the Name property of the element found.

Return Value:

true if the resulting node is an element and the Name property matches the specified string.false if a node type other than XmlNodeType.Element was found or if the element Name property does not match the specified string.

Exceptions

Exception Type	Condition
XmlException	Incorrect XML is encountered in the input stream.

This method skips white space, comments, and processing instructions until the reader is positioned on a content node. The method then tests if the current node is an element.

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Inherited
See base class member description: System.Xml.XmlReader.IsStartElement

Summary

Calls XmlReader.MoveToContent and tests if the current content node is a start tag or empty element tag and if the XmlReader.LocalName and XmlReader.NamespaceURI properties of the element found match the given strings.

C# Syntax:

public virtual bool IsStartElement(    string localname,    string ns );

localname

The string to match against the LocalName property of the element found.

ns

The string to match against the NamespaceURI property of the element found.

Return Value:

true if the resulting node is an element.false if a node type other than XmlNodeType.Element was found or if the LocalName and NamespaceURI properties of the element do not match the specified strings.

Exceptions

Exception Type	Condition
XmlException	Incorrect XML is encountered in the input stream.

This method skips white space, comments, and processing instructions until the reader is positioned on a content node. The method then tests if the current node is an element.

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Summary

Resolves a namespace prefix in the current element's scope.

C# Syntax:

public override string LookupNamespace(    string prefix );

prefix

The prefix whose namespace URI you want to resolve. To match the default namespace, pass an empty string. This string does not have to be atomized.

Return Value:

The namespace URI to which the prefix maps or null if no matching prefix is found.

              <root xmlns:a="urn:456">
               <item>
               <ref href="a:b"/>
               </item>
              </root>
               
            

In the preceding XML, if the reader is positioned on the href attribute, the prefix a is resolved by calling reader.LookupNamesapce("a") . The returned string is urn:456 .

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Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:

protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Summary

Moves to the attribute with the specified index.

C# Syntax:

public override void MoveToAttribute(    int attributeIndex );

attributeIndex

The index of the attribute.

Exceptions

Exception Type	Condition
ArgumentOutOfRangeException	The i parameter is less than 0 or greater than or equal to XmlReader.AttributeCount.

The following example reads all the attributes on the root node.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the attributes on the root element.
       reader.MoveToContent();
       if (reader.HasAttributes){
         for (int i=0; i<reader.AttributeCount; i++){
            reader.MoveToAttribute(i);
            Console.WriteLine("{0} = {1}", reader.Name, reader.Value);
         }
         //Return the reader to the book element.
         reader.MoveToElement();
       }

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Moves to the attribute with the specified name.

C# Syntax:

public override bool MoveToAttribute(    string name );

name

The qualified name of the attribute.

Return Value:

true if the attribute is found; otherwise, false. If false, the reader's position does not change.

After calling this method, the XmlNodeReader.Name, XmlNodeReader.NamespaceURI, and XmlNodeReader.Prefix properties reflect the properties of that attribute.

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Summary

Moves to the attribute with the specified local name and namespace URI.

C# Syntax:

public override bool MoveToAttribute(    string name,    string namespaceURI );

name

The local name of the attribute.

namespaceURI

The namespace URI of the attribute.

Return Value:

true if the attribute is found; otherwise, false. If false, the reader's position does not change.

After calling this method, the XmlNodeReader.Name, XmlNodeReader.NamespaceURI, and XmlNodeReader.Prefix properties reflect the properties of that attribute.

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Inherited
See base class member description: System.Xml.XmlReader.MoveToContent

Summary

Checks whether the current node is a content (non-white space text, CDATA, Element, EndElement, EntityReference, or EndEntity) node. If the node is not a content node, the reader skips ahead to the next content node or end of file. It skips over nodes of the following type: ProcessingInstruction, DocumentType, Comment, Whitespace, or SignificantWhitespace.

C# Syntax:

public virtual XmlNodeType MoveToContent();

Return Value:

The XmlReader.NodeType of the current node found by the method or XmlNodeType.None if the reader has reached the end of the input stream.

Exceptions

Exception Type	Condition
XmlException	Incorrect XML encountered in the input stream.

If the current node is an attribute node, this method moves the reader back to the element that owns the attribute.

This is useful when you want to write code that can skip over random XML markup without breaking. For example, suppose you have the following code:

if (reader.MoveToContent() == XmlNodeType.Element && reader.Name == "price") 
 {
    _price = reader.ReadString();
 }

    

This code can handle the following inputs without breaking:

<price>123.4</price>

and

<?xml version="1.0"><!DOCTYPE price SYSTEM "abc"><price>123.4</price>

and

<?xml version="1.0"><!DOCTYPE price SYSTEM "abc" [<!ENTTIY p "123.4">]><price>&p;</price>

and

<!-- some test comment --><?processing instruction?><price>123.4</price>

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Summary

Moves to the element that contains the current attribute node.

C# Syntax:

public override bool MoveToElement();

Return Value:

true if the reader is positioned on an attribute (the reader moves to the element that owns the attribute); false if the reader is not positioned on an attribute (the position of the reader does not change).

Use this method to return to an element after navigating through its attributes. This method moves the reader to one of the following node types: Element, DocumentType, or XmlDeclaration.

The following example reads all the attributes on the root node.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the attributes on the root element.
       reader.MoveToContent();
       if (reader.HasAttributes){
         for (int i=0; i<reader.AttributeCount; i++){
            reader.MoveToAttribute(i);
            Console.WriteLine("{0} = {1}", reader.Name, reader.Value);
         }
         //Return the reader to the book element.
         reader.MoveToElement();
       }

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Moves to the first attribute.

C# Syntax:

public override bool MoveToFirstAttribute();

Return Value:

true if an attribute exists (the reader moves to the first attribute); otherwise, false (the position of the reader does not change).

The following example gets the value of the first attribute in the.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78' publicationdate='1987'> " +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the genre attribute.
       reader.MoveToContent();
       reader.MoveToFirstAttribute();
       string genre=reader.Value;
       Console.WriteLine("The genre value: " + genre);

     } 
     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Moves to the next attribute.

C# Syntax:

public override bool MoveToNextAttribute();

Return Value:

true if there is a next attribute; false if there are no more attributes.

If the current node is not an attribute node, this method is equivalent to XmlNodeReader.MoveToFirstAttribute. If MoveToNextAttribute returns true, the reader moves to the next attribute; otherwise, the position of the reader does not change.

The following example reads a book.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book genre='novel' ISBN='1-861003-78'> " +
                   "<title>Pride And Prejudice</title>" +
                   "<price>19.95</price>" +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Read the attributes on the book element.
       reader.MoveToContent();
       while (reader.MoveToNextAttribute())
       {
         Console.WriteLine("{0} = {1}", reader.Name, reader.Value);
       }

       //Move the reader to the title element.
       reader.Read();

       //Read the title and price elements.
       Console.WriteLine(reader.ReadElementString());
       Console.WriteLine(reader.ReadElementString());

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
} // End class

    

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Summary

Reads the next node from the stream.

C# Syntax:

public override bool Read();

Return Value:

true if the next node was read successfully; false if there are no more nodes to read.

When a reader is first created and initialized, there is no information available. You must call Read to read the first node.

The following example reads an XML and displays each node.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  private const String filename = "items.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {           
        //Create an XmlNodeReader to read the XmlDocument.
        XmlDocument doc = new XmlDocument();
        doc.Load(filename);
        reader = new XmlNodeReader(doc);

        //Parse the file and display each of the nodes.
        while (reader.Read())
        {
           switch (reader.NodeType)
           {
             case XmlNodeType.Element:
               Console.Write("<{0}>", reader.Name);
               break;
             case XmlNodeType.Text:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.CDATA:
               Console.Write(reader.Value);
               break;
             case XmlNodeType.ProcessingInstruction:
               Console.Write("<?{0} {1}?>", reader.Name, reader.Value);
               break;
             case XmlNodeType.Comment:
               Console.Write("<!--{0}-->", reader.Value);
               break;
             case XmlNodeType.XmlDeclaration:
               Console.Write("<?xml version='1.0'?>");
               break;
             case XmlNodeType.Document:
               break;
             case XmlNodeType.EndElement:
               Console.Write("</{0}>", reader.Name);
               break;
           }       
          }           
        }

     finally
     {
       if (reader!=null)
         reader.Close();
     }
  }
} // End class

    

The example uses the file, items.xml, as input.

<?xml version="1.0"?>
<!-- This is a sample XML document -->
<!DOCTYPE Items [<!ENTITY number "123">]>
<Items>
  <Item>Test with an entity: &number;</Item>
  <Item>test with a child element <more/> stuff</Item>
  <Item>test with a CDATA section <![CDATA[<456>]]> def</Item>
  <Item>Test with a char entity: &#65;</Item>
  <!-- Fourteen chars in this element.-->
  <Item>1234567890ABCD</Item>
</Items>

    

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Summary

Parses the attribute value into one or more Text, EntityReference, or EndEntity nodes.

C# Syntax:

public override bool ReadAttributeValue();

Return Value:

true if there are nodes to return.

false if the reader is not positioned on an attribute node when the initial call is made or if all the attribute values have been read.

An empty attribute, such as, misc="" , returns true with a single node with a value of String.Empty.

Use this method after calling XmlNodeReader.MoveToAttribute to read through the text or entity reference nodes that make up the attribute value. The XmlNodeReader.Depth of the attribute value nodes is one plus the depth of the attribute node; it increments and decrements by one when you step into and out of general entity references.

The following example reads an attribute with text and entity reference nodes.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load an XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<!DOCTYPE book [<!ENTITY h 'harcover'>]>" +
                   "<book genre='novel' misc='sale-item &h; 1987'>" +
                   "</book>");
        
       //Create the reader. 
       reader = new XmlNodeReader(doc);

       //Read the misc attribute. The attribute is parsed into multiple 
       //text and entity reference nodes.
       reader.MoveToContent();
       reader.MoveToAttribute("misc");
       while (reader.ReadAttributeValue()){
          if (reader.NodeType==XmlNodeType.EntityReference)
            //To expand the entity, call ResolveEntity.
            Console.WriteLine("{0} {1}", reader.NodeType, reader.Name);
          else
             Console.WriteLine("{0} {1}", reader.NodeType, reader.Value);
        } 
     } 
     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
} // End class

    

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Inherited
See base class member description: System.Xml.XmlReader.ReadElementString

Summary

Reads a text-only element.

C# Syntax:

public virtual string ReadElementString();

Return Value:

The text contained in the element that was read. An empty string if the element is empty ( <item></item> or <item/> ).

Exceptions

Exception Type	Condition
XmlException	The next content node is not a start tag; or the element found does not contain a simple text value.

This is a helper method for reading simple text-only elements. It calls XmlReader.MoveToContent to find the next content node and then parses its value as a simple string.

Using the XML, <name>Arlene Huff</name> , ReadElementString consumes the element and returns the string Arlene Huff.

This method cannot handle any markup (child elements, comments, processing instructions, and so on) inside the name element, but it can concatenate multiple adjacent text and CDATA blocks.

The following example uses ReadElementString to read the contents of the element nodes.

using System;
using System.IO;
using System.Xml;

//Reads an XML fragment

public class Sample
{
  private const String filename = "book.xml";

  public static void Main()
  {
    XmlTextReader reader = null;

    try
    {           
      //Load the file and ignore all whitespace.
      reader = new XmlTextReader(filename);
      reader.WhitespaceHandling = WhitespaceHandling.None;

      //Moves the reader to the root element.
      reader.MoveToContent();

      //Read the title and price elements.
      Console.WriteLine("Content of the title element: {0}", reader.ReadElementString());
      Console.WriteLine("Content of the price element: {0}", reader.ReadElementString());; 
         
    }
    finally
    {
      if (reader!=null)
        reader.Close();
    }
  }
} // End class

    

The example uses the data file book.xml:

<!--sample XML fragment-->
<book genre='novel' ISBN='1-861003-78' misc='sale-item'>
  <title>The Handmaid's Tale</title>
  <price>14.95</price>
</book>

    

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Inherited
See base class member description: System.Xml.XmlReader.ReadElementString

Summary

Checks that the XmlReader.Name property of the element found matches the given string before reading a text-only element.

C# Syntax:

public virtual string ReadElementString(    string name );

name

The name to check.

Return Value:

The text contained in the element that was read. An empty string if the element is empty ( <item></item> or <item/> ).

Exceptions

Exception Type	Condition
XmlException	If the next content node is not a start tag; if the element Name does not match the given argument; or if the element found does not contain a simple text value.

This is a helper method for reading simple text-only elements. It calls XmlReader.MoveToContent to find the next content node and then parses its value as a simple string.

Using the XML, <name>Arlene Huff</name> , ReadElementString consumes the element and returns the string Arlene Huff.

This method cannot handle any markup (child elements, comments, processing instructions, and so on) inside the name element, but it can concatenate multiple adjacent text and CDATA blocks.

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Inherited
See base class member description: System.Xml.XmlReader.ReadElementString

Summary

Checks that the XmlReader.LocalName and XmlReader.NamespaceURI properties of the element found matches the given strings before reading a text-only element.

C# Syntax:

public virtual string ReadElementString(    string localname,    string ns );

localname

The local name to check.

ns

The namespace URI to check.

Return Value:

The text contained in the element that was read. An empty string if the element is empty ( <item></item> or <item/> ).

Exceptions

Exception Type	Condition
XmlException	If the next content node is not a start tag; if the element LocalName or NamespaceURI do not match the given arguments; or if the element found does not contain a simple text value.

This is a helper method for reading simple text-only elements. It calls XmlReader.MoveToContent to find the next content node and then parses its value as a simple string.

Using the XML, <name>Arlene Huff</name> , ReadElementString consumes the element and returns the string Arlene Huff.

This method cannot handle any markup (child elements, comments, processing instructions, and so on) inside the name element, but it can concatenate multiple adjacent text and CDATA blocks.

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Inherited
See base class member description: System.Xml.XmlReader.ReadEndElement

Summary

Checks that the current content node is an end tag and advances the reader to the next node.

C# Syntax:

public virtual void ReadEndElement();

Exceptions

Exception Type	Condition
XmlException	The current node is not an end tag or if incorrect XML is encountered in the input stream.

The following example reads an XML document using the XmlReader.ReadStartElement and ReadEndElement methods.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {

     //Create the reader.
     XmlTextReader  reader = new XmlTextReader("book3.xml");

     //Parse the XML document.  ReadString is used to 
     //read the text content of the elements.
     reader.Read(); 
     reader.ReadStartElement("book");  
     reader.ReadStartElement("title");   
     Console.Write("The content of the title element:  ");
     Console.WriteLine(reader.ReadString());
     reader.ReadEndElement();
     reader.ReadStartElement("price");
     Console.Write("The content of the price element:  ");
     Console.WriteLine(reader.ReadString());
     reader.ReadEndElement();
     reader.ReadEndElement();

     //Close the reader.
     reader.Close();
     
  }
} // End class

    

The example uses the file, book3.xml, as input.

<book>
  <title>Pride And Prejudice</title>
  <price>19.95</price>
</book>

    

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Summary

Reads all the content, including markup, as a string.

C# Syntax:

public override string ReadInnerXml();

Return Value:

All the XML content, including markup, in the current node. If the current node has no children, an empty string is returned.

If the current node is neither an element nor attribute, an empty string is returned.

This method returns all the content of the current node including the markup. The current node (start tag) and corresponding end node (end tag) are not returned. For example, if you had the following:

              <node>
               this <child id="123"/>
              </node>
               
            

ReadInnerXml returns this <child id="123"/>

This method handles element and attribute nodes in the following way:

Node Type	Child Content	Return Value	Position After the Call
Element	<item>text</item>	text	After the end tag.
Attribute	<item attr1="val1" attr2="val2">text</item>	val1	Remains on the attribute node attr1 .

If the reader is positioned on a leaf node, calling ReadInnerXml is equivalent to calling XmlNodeReader.Read.

This method also checks for well-formed XML.

The following example compares the ReadInnerXml and XmlNodeReader.ReadOuterXml methods.

using System;
using System.IO;
using System.Xml;

//Reads an XML fragment

public class Sample
{
  private const String filename = "2books.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       XmlDocument doc = new XmlDocument();
       doc.Load(filename);

       reader = new XmlNodeReader(doc);

       //Moves the reader to the root element.
       reader.MoveToContent();

       //Moves the reader to the book node.
       reader.Read(); 

       //Note that ReadInnerXml only returns the markup of the node's children
       //so the book's attributes are not returned.
       Console.WriteLine("Read the first book using ReadInnerXml...");
       Console.WriteLine(reader.ReadInnerXml());

       //ReadOuterXml returns the markup for the current node and its children
       //so the book's attributes are also returned.
       Console.WriteLine("\r\nRead the second book using ReadOuterXml...");
       Console.WriteLine(reader.ReadOuterXml());                    

    }
    finally
    {
      if (reader!=null)
        reader.Close();
    }
  }
} // End class

    

The example uses the file, 2books.xml, as input.

<!--sample XML fragment-->
<bookstore>
  <book genre='novel' ISBN='10-861003-324'>
    <title>The Handmaid's Tale</title>
    <price>19.95</price>
  </book>
  <book genre='novel' ISBN='1-861001-57-5'>
    <title>Pride And Prejudice</title>
    <price>24.95</price>
  </book>
</bookstore>

    

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Summary

Reads the content, including markup, representing this node and all its children.

C# Syntax:

public override string ReadOuterXml();

Return Value:

If the reader is positioned on an element or an attribute node, this method returns all the XML content, including markup, of the current node and all its children; otherwise, it returns an empty string.

This method is similar to XmlNodeReader.ReadInnerXml except it also returns the start and end tags.

This method handles element and attribute nodes in the following manner:

Node Type	Child Content	Return Value	Position After the Call
Element	<item>text</item>	<item>text</item>	After the end tag.
Attribute	<item attr1="val1" attr2="val2">text</item>	attr="val1"	Remains on the attribute node attr1 .

If the reader is positioned on a leaf node, calling ReadOuterXml is equivalent to calling XmlNodeReader.Read.

This method also checks for well-formed XML.

The following example compares the XmlNodeReader.ReadInnerXml and ReadOuterXml methods.

using System;
using System.IO;
using System.Xml;

//Reads an XML fragment

public class Sample
{
  private const String filename = "2books.xml";

  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       XmlDocument doc = new XmlDocument();
       doc.Load(filename);

       reader = new XmlNodeReader(doc);

       //Moves the reader to the root element.
       reader.MoveToContent();

       //Moves the reader to the book node.
       reader.Read(); 

       //Note that ReadInnerXml only returns the markup of the node's children
       //so the book's attributes are not returned.
       Console.WriteLine("Read the first book using ReadInnerXml...");
       Console.WriteLine(reader.ReadInnerXml());

       //ReadOuterXml returns the markup for the current node and its children
       //so the book's attributes are also returned.
       Console.WriteLine("\r\nRead the second book using ReadOuterXml...");
       Console.WriteLine(reader.ReadOuterXml());                    

    }
    finally
    {
      if (reader!=null)
        reader.Close();
    }
  }
} // End class

    

The example uses the file, 2books.xml, as input.

<!--sample XML fragment-->
<bookstore>
  <book genre='novel' ISBN='10-861003-324'>
    <title>The Handmaid's Tale</title>
    <price>19.95</price>
  </book>
  <book genre='novel' ISBN='1-861001-57-5'>
    <title>Pride And Prejudice</title>
    <price>24.95</price>
  </book>
</bookstore>

    

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Inherited
See base class member description: System.Xml.XmlReader.ReadStartElement

Summary

Checks that the current node is an element and advances the reader to the next node.

C# Syntax:

public virtual void ReadStartElement();

Exceptions

Exception Type	Condition
XmlException	XmlReader.IsStartElement returns false.

This method calls XmlReader.IsStartElement followed by XmlReader.Read to position you on the content of that element found in the input stream.

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Inherited
See base class member description: System.Xml.XmlReader.ReadStartElement

Summary

Checks that the current content node is an element with the given XmlReader.Name and advances the reader to the next node.

C# Syntax:

public virtual void ReadStartElement(    string name );

name

The qualified name of the element.

Exceptions

Exception Type	Condition
XmlException	XmlReader.IsStartElement returns false or if the XmlReader.Name of the element does not match the given name.

A call to this method corresponds to a call to XmlReader.IsStartElement followed by a call to XmlReader.Read.

The following example parses an XML document using the ReadStartElement and XmlReader.ReadEndElement methods.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {

     //Create the reader.
     XmlTextReader  reader = new XmlTextReader("book3.xml");

     //Parse the XML document.  ReadString is used to 
     //read the text content of the elements.
     reader.Read(); 
     reader.ReadStartElement("book");  
     reader.ReadStartElement("title");   
     Console.Write("The content of the title element:  ");
     Console.WriteLine(reader.ReadString());
     reader.ReadEndElement();
     reader.ReadStartElement("price");
     Console.Write("The content of the price element:  ");
     Console.WriteLine(reader.ReadString());
     reader.ReadEndElement();
     reader.ReadEndElement();

     //Close the reader.
     reader.Close();
     
  }
} // End class

    

The example uses the file, book3.xml, as input.

<book>
  <title>Pride And Prejudice</title>
  <price>19.95</price>
</book>

    

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Inherited
See base class member description: System.Xml.XmlReader.ReadStartElement

Summary

Checks that the current content node is an element with the given XmlReader.LocalName and XmlReader.NamespaceURI and advances the reader to the next node.

C# Syntax:

public virtual void ReadStartElement(    string localname,    string ns );

localname

The local name of the element.

ns

The namespace URI of the element.

Exceptions

Exception Type	Condition
XmlException	XmlReader.IsStartElement returns false, or the XmlReader.LocalName and XmlReader.NamespaceURI properties of the element found do not match the given arguments.

A call to this method corresponds to a call to XmlReader.IsStartElement followed by a call to XmlReader.Read.

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Summary

Reads the contents of an element or text node as a string.

C# Syntax:

public override string ReadString();

Return Value:

The contents of the element or text-like node (This can include CDATA, Text nodes, and so on). This can be an empty string if the reader is positioned on something other than an element or text node, or if there is no more text content to return in the current context.

Note: The text node can be either an element or an attribute text node.

If positioned on an element, ReadString concatenates all text, significant white space, white space, and CData section node types together and returns the concatenated data as the element content. It stops when any markup is encountered. This could occur in a mixed content model, or when an element end tag is read.

If positioned on a text-like node, ReadString performs the same concatenation from the text node to the element end tag. If the reader is positioned on an attribute text node, ReadString has the same functionality as if the reader were position on the element start tag. It returns all the concatenated element text nodes.

The following example displays the text content of each of the elements.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<book>" +
                   "<title>Pride And Prejudice</title>" +
                   "<price>19.95</price>" +
                   "<misc/>" +
                   "</book>"); 

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);
  
       //Parse the XML and display the text content of each of the elements.
       while (reader.Read()){
         if (reader.IsStartElement()){
           if (reader.IsEmptyElement)
              Console.WriteLine("<{0}/>", reader.Name);
           else{
               Console.Write("<{0}> ", reader.Name);
               reader.Read(); //Read the start tag.
               if (reader.IsStartElement())  //Handle nested elements.
                   Console.Write("\r\n<{0}>", reader.Name);
               Console.WriteLine(reader.ReadString());  //Read the text content of the element.
           }
         }
       } 
       
     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
  
} // End class

    

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Summary

Resolves the entity reference for EntityReference nodes.

C# Syntax:

public override void ResolveEntity();

Exceptions

Exception Type	Condition
InvalidOperationException	The reader is not positioned on an EntityReference node.

If the reader is positioned on an EntityReference node (XmlNodeType.EntityReference), if XmlNodeReader.Read is called after calling this method, the entity replacement text is parsed. When the entity replacement text is finished, an EndEntity node is returned to close the entity reference scope.

Note After calling this method, if the entity is part of an attribute value, you must call XmlNodeReader.ReadAttributeValue to step into the entity.

The following example uses ResolveEntity to expand a general entity.

using System;
using System.IO;
using System.Xml;

public class Sample
{
  public static void Main()
  {
     XmlNodeReader reader = null;

     try
     {
       //Create and load an XML document. 
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<!DOCTYPE book [<!ENTITY h 'hardcover'>]>" +
                   "<book>" +
                   "<title>Pride And Prejudice</title>" +
                   "<misc>&h;</misc>" +
                   "</book>"); 

       //Create the reader.
       reader = new XmlNodeReader(doc);

       reader.MoveToContent();  //Move to the root element.
       reader.Read();  //Move to title start tag.
       reader.Skip();  //Skip the title element.
      
       //Read the misc start tag.  The reader is now positioned on
       //the entity reference node.
       reader.ReadStartElement(); 

       //You must call ResolveEntity to expand the entity reference.
       //The entity replacement text is then parsed and returned as a child node.
       Console.WriteLine("Expand the entity...");
       reader.ResolveEntity();  

       Console.WriteLine("The entity replacement text is returned as a text node.");
       reader.Read();  
       Console.WriteLine("NodeType: {0} Value: {1}", reader.NodeType ,reader.Value);

       Console.WriteLine("An EndEntity node closes the entity reference scope.");
       reader.Read();
       Console.WriteLine("NodeType: {0} Name: {1}", reader.NodeType,reader.Name); 
     
    }
    finally
    {
       if (reader != null)
         reader.Close();
    }
  }
}

    

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Summary

Skips the children of the current node.

C# Syntax:

public override void Skip();

For example, suppose you have the following XML input:

              <a name="bob" age="123">
                 <x/>abc<y/>
               </a>
               <b>
               ...
               </b>
                 
            

If the reader is positioned on the "<a>" node or any of its attributes, calling Skip positions the reader to the "<b>" node.

If the reader is positioned on a leaf node already (such as element "x" or the text node "abc"), calling Skip is the same as calling XmlNodeReader.Read.

This method checks for well-formed XML.

The following example reads the price element node in the XML document.

using System;
using System.IO;
using System.Xml;

public class Sample 
{
  public static void Main()
  {
    XmlNodeReader reader = null;

    try
    {
       //Create and load the XML document.
       XmlDocument doc = new XmlDocument();
       doc.LoadXml("<!-- sample XML -->" +
                   "<book>" +
                   "<title>Pride And Prejudice</title>" +
                   "<price>19.95</price>" +
                   "</book>");

       //Load the XmlNodeReader 
       reader = new XmlNodeReader(doc);

       reader.MoveToContent(); //Move to the book node.
       reader.Read();  //Read the book start tag.
       reader.Skip();   //Skip the title element.

       Console.WriteLine(reader.ReadOuterXml());  //Read the price element.

     } 

     finally 
     {
        if (reader != null)
          reader.Close();
      }
  }
} // End class

    

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Inherited
See base class member description: System.Object.ToString

C# Syntax:

public virtual string ToString();

For more information on members inherited from System.Object click on the link above.

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