XmlElementEventArgs Class

Definition

Namespace:

System.Xml.Serialization

Assembly:

System.Xml.XmlSerializer.dll

Source:

_Events.cs

Provides data for the UnknownElement event.

public ref class XmlElementEventArgs : EventArgs

public class XmlElementEventArgs : EventArgs

type XmlElementEventArgs = class
    inherit EventArgs

Public Class XmlElementEventArgs
Inherits EventArgs

Inheritance

Object

EventArgs

XmlElementEventArgs

Examples

The following example deserializes a class named Group from a file named UnknownElements.xml. Whenever an element is found in the file that has no corresponding member in the class, the UnknownElement event occurs. To try the example, paste the following XML code into a file named UnknownElements.xml.

<?xml version="1.0" encoding="utf-8"?>  
<Group xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">  
  <GroupName>MyGroup</GroupName>  
  <GroupSize>Large</GroupSize>  
  <GroupNumber>444</GroupNumber>  
  <GroupBase>West</GroupBase>  
</Group>  

#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;
using namespace System::Xml;
using namespace System::Xml::Schema;

public ref class Group
{
public:
   String^ GroupName;
};

public ref class Test
{
private:
   void Serializer_UnknownElement( Object^ sender, XmlElementEventArgs^ e )
   {
      Console::WriteLine( "Unknown Element" );
      Console::Write( "\t {0}", e->Element->Name );
      Console::WriteLine( " {0}", e->Element->InnerXml );
      Console::WriteLine( "\t LineNumber: {0}", e->LineNumber );
      Console::WriteLine( "\t LinePosition: {0}", e->LinePosition );
      Group^ x = dynamic_cast<Group^>(e->ObjectBeingDeserialized);
      Console::WriteLine( x->GroupName );
      Console::WriteLine( sender );
   }

public:
   void DeserializeObject( String^ filename )
   {
      XmlSerializer^ ser = gcnew XmlSerializer( Group::typeid );

      // Add a delegate to handle unknown element events.
      ser->UnknownElement += gcnew XmlElementEventHandler( this, &Test::Serializer_UnknownElement );

      // A FileStream is needed to read the XML document.
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
      Group^ g = dynamic_cast<Group^>(ser->Deserialize( fs ));
      fs->Close();
   }
};

int main()
{
   Test^ t = gcnew Test;

   // Deserialize the file containing unknown elements.
   t->DeserializeObject( "UnknownElements.xml" );
}

using System;
using System.IO;
using System.Xml.Serialization;
using System.Xml;
using System.Xml.Schema;

public class Group{
   public string GroupName;
}

public class Test{
   static void Main(){
      Test t = new Test();
      // Deserialize the file containing unknown elements.
      t.DeserializeObject("UnknownElements.xml");
   }
   private void Serializer_UnknownElement(object sender, XmlElementEventArgs e){
      Console.WriteLine("Unknown Element");
      Console.WriteLine("\t" + e.Element.Name + " " + e.Element.InnerXml);
      Console.WriteLine("\t LineNumber: " + e.LineNumber);
      Console.WriteLine("\t LinePosition: " + e.LinePosition);
      
      Group x  = (Group) e.ObjectBeingDeserialized;
      Console.WriteLine (x.GroupName);
      Console.WriteLine (sender.ToString());
   }
   private void DeserializeObject(string filename){
      XmlSerializer ser = new XmlSerializer(typeof(Group));
      // Add a delegate to handle unknown element events.
      ser.UnknownElement+=new XmlElementEventHandler(Serializer_UnknownElement);
      // A FileStream is needed to read the XML document.
     FileStream fs = new FileStream(filename, FileMode.Open);
     Group g = (Group) ser.Deserialize(fs);
     fs.Close();
    }
}

Imports System.IO
Imports System.Xml.Serialization
Imports System.Xml
Imports System.Xml.Schema

Public Class Group
   Public GroupName As String 
End Class

Public Class Test
   Shared Sub Main()
      Dim t As Test = new Test()
      ' Deserialize the file containing unknown elements.
      t.DeserializeObject("UnknownElements.xml")
   End Sub

   Private Sub Serializer_UnknownElement _
   (sender As Object , e As XmlElementEventArgs)
      Console.WriteLine("Unknown Element")
      Console.WriteLine(ControlChars.Tab & e.Element.Name + " " & e.Element.InnerXml)
      Console.WriteLine(ControlChars.Tab & e.LineNumber & ":"  & e.LineNumber)
      Console.WriteLine(ControlChars.Tab & e.LinePosition & ":"   & e.LinePosition)
      
      Dim x As Group = CType( e.ObjectBeingDeserialized, Group)
      Console.WriteLine (x.GroupName)
      Console.WriteLine (sender.ToString())
   End Sub
   
   Private Sub DeserializeObject(filename As String)
      Dim ser As XmlSerializer = new XmlSerializer(GetType(Group))
      ' Add a delegate to handle unknown element events.
      AddHandler ser.UnknownElement, _
      AddressOf Serializer_UnknownElement 
      ' A FileStream is needed to read the XML document.
     Dim fs As FileStream  = new FileStream(filename, FileMode.Open)
     Dim g  As Group = CType(ser.Deserialize(fs),Group)
     fs.Close()
   End Sub
End Class

Remarks

For more information about handling events, see Handling and Raising Events and Handling and Raising Events.

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

Properties

Element	Gets the object that represents the unknown XML element.
ExpectedElements	Gets a comma-delimited list of XML element names expected to be in an XML document instance.
LineNumber	Gets the line number where the unknown element was encountered if the XML reader is an XmlTextReader.
LinePosition	Gets the place in the line where the unknown element occurs if the XML reader is an XmlTextReader.
ObjectBeingDeserialized	Gets the object the XmlSerializer is deserializing.

Methods

Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)