UnreferencedObjectEventHandler Delegate
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UnreferencedObjectEventHandler Delegate


Represents the method that handles the UnreferencedObject event of an XmlSerializer.

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

public delegate void UnreferencedObjectEventHandler(
	object sender,
	UnreferencedObjectEventArgs e


Type: System.Object

The source of the event.

Type: System.Xml.Serialization.UnreferencedObjectEventArgs

An UnreferencedObjectEventArgs that contains the event data.

When you create an UnreferencedObjectEventHandler delegate, you identify the method that handles the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see NIB: Events and Delegates

The UnreferencedObject event occurs only when you call the Deserialize method.

The following example adds an UnreferencedObjectEventHandler to an XmlSerializer. The event is handled by the Serializer_UnreferencedObject method. To run the example, cut and paste the following XML into a file named UnrefObj.xml.

  <Group xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" id="id1" n1:GroupName=".NET" xmlns:n1="http://www.cpandl.com">
<Vehicle id="id2" n1:type="Vehicle" xmlns:n1="http://www.w3.org/2001/XMLSchema-instance">
    <licenseNumber xmlns:q1="http://www.w3.org/2001/XMLSchema" n1:type="q1:string">ABCD</licenseNumber>
<Vehicle id="id3" n1:type="Vehicle" xmlns:n1="http://www.w3.org/2001/XMLSchema-instance">
    <licenseNumber xmlns:q1="http://www.w3.org/2001/XMLSchema" n1:type="q1:string">1234</licenseNumber>
using System;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using System.Xml.Schema;

// You must use the SoapIncludeAttribute to inform the XmlSerializer
// that the Vehicle type should be recognized when deserializing.
public class Group
   public string GroupName;
   public Vehicle GroupVehicle;
public class Vehicle
   public string licenseNumber;

public class Run
   public static void Main()
      Run test = new Run();

   public void DeserializeObject(string filename)
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping myMapping = 
      (new SoapReflectionImporter().ImportTypeMapping(
      XmlSerializer mySerializer =  
      new XmlSerializer(myMapping);

      mySerializer.UnreferencedObject += 
      new UnreferencedObjectEventHandler

      // Reading the file requires an  XmlTextReader.
      XmlTextReader reader= 
      new XmlTextReader(filename);

      // Deserialize and cast the object.
      Group myGroup; 
      myGroup = (Group) mySerializer.Deserialize(reader);

   private void Serializer_UnreferencedObject
   (object sender, UnreferencedObjectEventArgs e){
      Console.WriteLine("ID: " + e.UnreferencedId);
      Console.WriteLine("UnreferencedObject: " + e.UnreferencedObject);
      Vehicle myVehicle = (Vehicle) e.UnreferencedObject;
      Console.WriteLine("License: " + myVehicle.licenseNumber);

// The file named "UnrefObj.xml" should contain this XML:

// <wrapper>

//  <Group xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
//xmlns:xsd="http://www.w3.org/2001/XMLSchema" id="id1" 
//n1:GroupName=".NET" xmlns:n1="http://www.cpandl.com">
//   </Group>

//<Vehicle id="id2" n1:type="Vehicle" 
//   <licenseNumber xmlns:q1="http://www.w3.org/2001/XMLSchema" 
//   </Vehicle>

//<Vehicle id="id3" n1:type="Vehicle" 
//    <licenseNumber xmlns:q1="http://www.w3.org/2001/XMLSchema" 
//  </Vehicle>


.NET Framework
Available since 1.1
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