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XmlSerializer.UnknownNode Event

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

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

'Declaration
Public Event UnknownNode As XmlNodeEventHandler

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.

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


Imports System
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>
'      <Elmo>
'         <Glue>element</Glue>
'      </Elmo>
'  </coho:ThingInfo>
'/Group>


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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