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XmlSerializer.UnknownNode Event

  • Reference

Definition

Namespace:
System.Xml.Serialization
Assembly:
System.Xml.XmlSerializer.dll
Assembly:
System.Xml.dll
Assembly:
netstandard.dll
Source:
XmlSerializer.cs
Source:
XmlSerializer.cs
Source:
XmlSerializer.cs

Occurs when the XmlSerializer encounters an XML node of unknown type during deserialization.

public:
 event System::Xml::Serialization::XmlNodeEventHandler ^ UnknownNode;
public event System.Xml.Serialization.XmlNodeEventHandler UnknownNode;
member this.UnknownNode : System.Xml.Serialization.XmlNodeEventHandler 
Public Custom Event UnknownNode As XmlNodeEventHandler

Event Type

XmlNodeEventHandler

Examples

The following example prints the type of any encountered unknown node.

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

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

public ref class Group
{
public:

   // Only the GroupName field will be known.
   String^ GroupName;
};

public ref class Test
{
public:
   static void main()
   {
      Test^ t = gcnew Test;
      t->DeserializeObject( "UnknownNodes.xml" );
   }

private:
   void DeserializeObject( String^ filename )
   {
      XmlSerializer^ mySerializer = gcnew XmlSerializer( Group::typeid );
      FileStream^ fs = gcnew FileStream( filename,FileMode::Open );
      mySerializer->UnknownNode += gcnew XmlNodeEventHandler( this, &Test::serializer_UnknownNode );
      Group^ myGroup = dynamic_cast<Group^>(mySerializer->Deserialize( fs ));
      fs->Close();
   }

private:
   void serializer_UnknownNode( Object^ /*sender*/, XmlNodeEventArgs^ e )
   {
      Console::WriteLine( "UnknownNode Name: {0}", e->Name );
      Console::WriteLine( "UnknownNode LocalName: {0}", e->LocalName );
      Console::WriteLine( "UnknownNode Namespace URI: {0}", e->NamespaceURI );
      Console::WriteLine( "UnknownNode Text: {0}", e->Text );
      XmlNodeType myNodeType = e->NodeType;
      Console::WriteLine( "NodeType: {0}", myNodeType );
      Group^ myGroup = dynamic_cast<Group^>(e->ObjectBeingDeserialized);
      Console::WriteLine( "GroupName: {0}", myGroup->GroupName );
      Console::WriteLine();
   }
};

int main()
{
   Test::main();
}

/* Paste this XML into a file named UnknownNodes:
<?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" xmlns:coho = "http://www.cohowinery.com" 

xmlns:cp="http://www.cpandl.com">
   <coho:GroupName>MyGroup</coho:GroupName>
   <cp:GroupSize>Large</cp:GroupSize>
   <cp:GroupNumber>444</cp:GroupNumber>
   <coho:GroupBase>West</coho:GroupBase>
   <coho:ThingInfo>
      <Number>1</Number>
      <Name>Thing1</Name>
      <Elmo>
         <Glue>element</Glue>
      </Elmo>
   </coho:ThingInfo>
</Group>
*/

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

public class Group{
   // Only the GroupName field will be known.
   public string GroupName;
}

public class Test{
   static void Main(){
      Test t = new Test();
      t.DeserializeObject("UnknownNodes.xml");
   }

   private void DeserializeObject(string filename){
      XmlSerializer mySerializer = new XmlSerializer(typeof(Group));
      FileStream fs = new FileStream(filename, FileMode.Open);
      mySerializer.UnknownNode += new
      XmlNodeEventHandler(serializer_UnknownNode);
      Group myGroup = (Group) mySerializer.Deserialize(fs);
      fs.Close();
   }
   private void serializer_UnknownNode
   (object sender, XmlNodeEventArgs e){
      Console.WriteLine
      ("UnknownNode Name: {0}", e.Name);
      Console.WriteLine
      ("UnknownNode LocalName: {0}" ,e.LocalName);
      Console.WriteLine
      ("UnknownNode Namespace URI: {0}", e.NamespaceURI);
      Console.WriteLine
      ("UnknownNode Text: {0}", e.Text);

      XmlNodeType myNodeType = e.NodeType;
      Console.WriteLine("NodeType: {0}", myNodeType);

      Group myGroup = (Group) e.ObjectBeingDeserialized;
      Console.WriteLine("GroupName: {0}", myGroup.GroupName);
      Console.WriteLine();
   }
}
/* Paste this XML into a file named UnknownNodes:
<?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" xmlns:coho = "http://www.cohowinery.com"

xmlns:cp="http://www.cpandl.com">
   <coho:GroupName>MyGroup</coho:GroupName>
   <cp:GroupSize>Large</cp:GroupSize>
   <cp:GroupNumber>444</cp:GroupNumber>
   <coho:GroupBase>West</coho:GroupBase>
   <coho:ThingInfo>
      <Number>1</Number>
      <Name>Thing1</Name>
      <Elmo>
         <Glue>element</Glue>
      </Elmo>
   </coho:ThingInfo>
</Group>
*/

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

Public Class Group
   ' Only the GroupName field will be known.
   Public GroupName As String
End Class

Public Class Test
   Shared Sub Main()
      Dim t As Test = New Test()
      t.DeserializeObject("UnknownNodes.xml")
   End Sub

   Private Sub DeserializeObject(filename As String )
      Dim mySerializer As XmlSerializer  = New XmlSerializer(GetType(Group))
      Dim fs As FileStream = New FileStream(filename, FileMode.Open)
      AddHandler mySerializer.UnknownNode, _
      AddressOf serializer_UnknownNode
      Dim myGroup As Group = _
      CType(mySerializer.Deserialize(fs), Group)
      fs.Close()
   End Sub
   
   Private Sub serializer_UnknownNode _
   (sender As object , e As XmlNodeEventArgs )
      Console.WriteLine _
      ("UnknownNode Name: {0}", e.Name)
      Console.WriteLine _
      ("UnknownNode LocalName: {0}" ,e.LocalName)
      Console.WriteLine _
      ("UnknownNode Namespace URI: {0}", e.NamespaceURI)
      Console.WriteLine _
      ("UnknownNode Text: {0}", e.Text)

      Dim myNodeType As XmlNodeType = e.NodeType
      Console.WriteLine("NodeType: {0}", myNodeType)
 
      Dim myGroup As Group = CType(e.ObjectBeingDeserialized, Group)
      Console.WriteLine("GroupName: {0}", myGroup.GroupName)
      Console.WriteLine()
   End Sub
End Class
' Paste this XML into a file named UnknownNodes:
'<?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" xmlns:coho = "http:'www.cohowinery.com" 

'xmlns:cp="http:'www.cpandl.com">
'   <coho:GroupName>MyGroup</coho:GroupName>
'   <cp:GroupSize>Large</cp:GroupSize>
'   <cp:GroupNumber>444</cp:GroupNumber>
'   <coho:GroupBase>West</coho:GroupBase>
'   <coho:ThingInfo>
'      <Number>1</Number>
'      <Name>Thing1</Name>
'         <Glue>element</Glue>
'  </coho:ThingInfo>
'/Group>

Remarks

By default, after calling the Deserialize method, the XmlSerializer ignores XML nodes of unknown types. However, you can use this event to handle such node types.

Applies to

See also