UnreferencedObjectEventHandler Delegate

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

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

'Declaration
Public Delegate Sub UnreferencedObjectEventHandler ( _
	sender As Object, _
	e As UnreferencedObjectEventArgs _
)
'Usage
Dim instance As New UnreferencedObjectEventHandler(AddressOf HandlerMethod)
/** @delegate */
public delegate void UnreferencedObjectEventHandler (
	Object sender, 
	UnreferencedObjectEventArgs e
)
Not applicable.

Parameters

sender

The source of the event.

e

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 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.

 <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" 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>
 <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>
   </Vehicle>
 </wrapper>
Imports System
Imports System.IO
Imports System.Text
Imports System.Xml
Imports System.Xml.Serialization
Imports System.Xml.Schema

' You must use the SoapIncludeAttribute to inform the XmlSerializer
' that the Vehicle type should be recognized when deserializing.
<SoapInclude(GetType(Vehicle))> _
Public Class Group
    Public GroupName As String 
   public GroupVehicle As Vehicle 
End Class

Public Class Vehicle
   Public licenseNumber As String 
End Class

 
Public Class Run
   Shared Sub Main()
      Dim test As Run = new Run()
      test.DeserializeObject("UnrefObj.xml")
   End Sub
   
   Public Sub DeserializeObject(filename As String)
      ' Create an instance of the XmlSerializer class.
      Dim myMapping As XmlTypeMapping = _
      (new SoapReflectionImporter().ImportTypeMapping _
      (GetType(Group)))
      Dim mySerializer As XmlSerializer =  _
      new XmlSerializer(myMapping)

      AddHandler mySerializer.UnreferencedObject, _
      AddressOf Serializer_UnreferencedObject

      ' Reading the file requires an  XmlTextReader.
      Dim reader As XmlTextReader = _
      new XmlTextReader(filename)
      reader.ReadStartElement()

      ' Deserialize and cast the object.
      Dim myGroup As Group  
      myGroup = CType( mySerializer.Deserialize(reader), Group)
      reader.ReadEndElement()
      reader.Close()
   End Sub
   
   Private Sub Serializer_UnreferencedObject _
   (sender As object , e As UnreferencedObjectEventArgs)
      Console.WriteLine("UnreferencedObject:")
      Console.WriteLine("ID: " + e.UnreferencedId)
      Console.WriteLine("UnreferencedObject: " + e.UnreferencedObject)
      Dim myVehicle As Vehicle = CType(e.UnreferencedObject, Vehicle)
      Console.WriteLine("License: " + myVehicle.licenseNumber)
       End Sub
 End Class
 
' The XML document should contain this information:

'<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" 
'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>

'<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>
'  </Vehicle>

'</wrapper>


import System.*;
import System.IO.*;
import System.Text.*;
import System.Xml.*;
import System.Xml.Serialization.*;
import System.Xml.Schema.*;
// You must use the SoapIncludeAttribute to inform the XmlSerializer
// that the Vehicle type should be recognized when deserializing.
/** @attribute SoapInclude(Vehicle.class)
 */
public class Group
{
    public String groupName;
    public Vehicle groupVehicle;
} //Group

/** @attribute SoapInclude(Vehicle.class)
 */
public class Vehicle
{
    public String licenseNumber;
} //Vehicle

public class Run
{
    public static void main(String[] args)
    {
        Run test = new Run();
        test.DeserializeObject("UnrefObj.xml");
    } //main

    public void DeserializeObject(String fileName)
    {
        // Create an instance of the XmlSerializer class.
        XmlTypeMapping myMapping = (new SoapReflectionImporter()).
            ImportTypeMapping(Group.class.ToType());

        XmlSerializer mySerializer = new XmlSerializer(myMapping);

        mySerializer.add_UnreferencedObject(new UnreferencedObjectEventHandler(
            Serializer_UnreferencedObject));
        // Reading the file requires an  XmlTextReader.
        XmlTextReader reader = new XmlTextReader(fileName);
        reader.ReadStartElement();
        // Deserialize and cast the object.
        Group myGroup;
        myGroup = (Group)mySerializer.Deserialize(reader);
        reader.ReadEndElement();
        reader.Close();
    } //DeserializeObject

    private void Serializer_UnreferencedObject(Object sender,
        UnreferencedObjectEventArgs e)
    {
        Console.WriteLine("UnreferencedObject:");
        Console.WriteLine("ID: " + e.get_UnreferencedId());
        Console.WriteLine("UnreferencedObject: " + e.get_UnreferencedObject());
        Vehicle myVehicle = (Vehicle)e.get_UnreferencedObject();
        Console.WriteLine("License: " + myVehicle.licenseNumber);
    } //Serializer_UnreferencedObject
} //Run

// 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" 
//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>
//<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>
//  </Vehicle>
//</wrapper>

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0

XNA Framework

Supported in: 1.0

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