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XmlNodeReader.ResolveEntity Method

Resolves the entity reference for EntityReference nodes.

Namespace:  System.Xml
Assembly:  System.Xml (in System.Xml.dll)

public override void ResolveEntity()

ExceptionCondition
InvalidOperationException

The reader is not positioned on an EntityReference node.

NoteNote

In the .NET Framework version 2.0, the recommended practice is to create XmlReader instances using the XmlReaderSettings class and the Create method. This allows you to take full advantage of all the new features introduced in the .NET Framework. For more information, see Creating XML Readers.

If the reader is positioned on an EntityReference node (XmlNodeType.EntityReference), if 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.

NoteNote

After calling this method, if the entity is part of an attribute value, you must call 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();
    }
  }
}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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