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)

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
Available since 1.1
Return to top
Show: