UnreferencedObjectEventHandler Delegate
Represents the method that handles the UnreferencedObject event of an XmlSerializer.
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)
Parameters
- sender
- Type: System.Object
The source of the event.
- e
- 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 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>
#using <mscorlib.dll>
#using <System.Xml.dll>
using namespace System;
using namespace System::IO;
using namespace System::Text;
using namespace System::Xml;
using namespace System::Xml::Serialization;
using namespace System::Xml::Schema;
__gc public class Vehicle;
[SoapInclude(__typeof(Vehicle))]
__gc public class Vehicle
{
public:
String* licenseNumber;
};
// You must use the SoapIncludeAttribute to inform the XmlSerializer
// that the Vehicle type should be recognized when deserializing.
[SoapInclude(__typeof(Vehicle))]
__gc public class Group
{
public:
String* GroupName;
Vehicle * GroupVehicle;
};
__gc public class Run
{
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
(this, &Run::Serializer_UnreferencedObject);
// Reading the file requires an XmlTextReader.
XmlTextReader* reader = new XmlTextReader(filename);
reader -> ReadStartElement();
// Deserialize and cast the object.
Group * myGroup;
myGroup = dynamic_cast<Group*>(mySerializer -> Deserialize(reader));
reader -> ReadEndElement();
reader -> Close();
}
private:
void Serializer_UnreferencedObject(Object* /*sender*/, UnreferencedObjectEventArgs * e)
{
Console::WriteLine(S"UnreferencedObject:");
Console::WriteLine(S"ID: {0}", e -> UnreferencedId);
Console::WriteLine(S"UnreferencedObject: {0}", e -> UnreferencedObject);
Vehicle * myVehicle = dynamic_cast<Vehicle*>(e -> UnreferencedObject);
Console::WriteLine(S"License: {0}", myVehicle -> licenseNumber);
}
};
int main()
{
Run* test = new Run();
test -> DeserializeObject(S"UnrefObj.xml");
}
// The file named S"UnrefObj.xml" should contain this XML:
// <wrapper>
// <Group xmlns:xsi=S"http://www.w3.org/2001/XMLSchema-instance"
//xmlns:xsd=S"http://www.w3.org/2001/XMLSchema" id=S"id1"
//n1:GroupName=S".NET" xmlns:n1=S"http://www.cpandl.com">
// </Group>
//<Vehicle id=S"id2" n1:type=S"Vehicle"
//xmlns:n1=S"http://www.w3.org/2001/XMLSchema-instance">
// <licenseNumber xmlns:q1=S"http://www.w3.org/2001/XMLSchema"
//n1:type=S"q1:String*">ABCD</licenseNumber>
// </Vehicle>
//<Vehicle id=S"id3" n1:type=S"Vehicle"
//xmlns:n1=S"http://www.w3.org/2001/XMLSchema-instance">
// <licenseNumber xmlns:q1=S"http://www.w3.org/2001/XMLSchema"
//n1:type=S"q1:String*">1234</licenseNumber>
// </Vehicle>
//</wrapper>
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.