UnreferencedObjectEventHandler Delegar

Definição

public delegate void UnreferencedObjectEventHandler(System::Object ^ sender, UnreferencedObjectEventArgs ^ e);

public delegate void UnreferencedObjectEventHandler(object sender, UnreferencedObjectEventArgs e);

type UnreferencedObjectEventHandler = delegate of obj * UnreferencedObjectEventArgs -> unit

Public Delegate Sub UnreferencedObjectEventHandler(sender As Object, e As UnreferencedObjectEventArgs)

Parâmetros

Exemplos

O exemplo seguinte adiciona um UnreferencedObjectEventHandler a um XmlSerializer. O evento é gerido pelo Serializer_UnreferencedObject método. Para executar o exemplo, corte e cole o seguinte XML num ficheiro chamado 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>

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.
[SoapInclude(typeof(Vehicle))]
public class Group
{
   public string GroupName;
   public Vehicle GroupVehicle;
}
 [SoapInclude(typeof(Vehicle))]
public class Vehicle
{
   public string licenseNumber;
}

public class Run
{
   public static void Main()
   {
      Run test = new Run();
      test.DeserializeObject("UnrefObj.xml");
   }
   
   public void DeserializeObject(string filename)
   {
      // Create an instance of the XmlSerializer class.
      XmlTypeMapping myMapping = 
      (new SoapReflectionImporter().ImportTypeMapping(
      typeof(Group)));
      XmlSerializer mySerializer =  
      new XmlSerializer(myMapping);
 
      mySerializer.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();
   }

   private void Serializer_UnreferencedObject
   (object sender, UnreferencedObjectEventArgs e){
      Console.WriteLine("UnreferencedObject:");
      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:


//  <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>

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:


'  <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>

Observações

Quando crias um UnreferencedObjectEventHandler delegado, identificas o método que gere o evento. Para associar o evento ao seu gestor de eventos, adicione uma instância do delegado ao evento. O gestor de eventos é chamado sempre que o evento ocorre, a menos que remova o delegado. Para mais informações sobre os delegados gestores de eventos, consulte Gestão e Levantamento de Eventos

O UnreferencedObject evento ocorre apenas quando se chama o Deserialize método.