XmlSerializer.UnknownAttribute Event
Assembly: System.Xml (in system.xml.dll)
'Declaration Public Event UnknownAttribute As XmlAttributeEventHandler 'Usage Dim instance As XmlSerializer Dim handler As XmlAttributeEventHandler AddHandler instance.UnknownAttribute, handler
/** @event */ public void add_UnknownAttribute (XmlAttributeEventHandler value) /** @event */ public void remove_UnknownAttribute (XmlAttributeEventHandler value)
JScript supports the use of events, but not the declaration of new ones.
By default, after calling the Deserialize method, the XmlSerializer ignores XML attributes of unknown types. However, you can use this event to handle such node types.
If the instance of the class being deserialized contains a field that returns an array of XmlAttribute objects and an XmlAnyAttributeAttribute has been applied to the field, the UnknownAttribute event does not occur. Instead, all unknown XML attributes are collected into the array.
The following example prints information about any unknown attributes encountered while deserializing an XML document.
Imports System Imports System.IO Imports System.Xml.Serialization Imports System.Xml Imports System.Xml.Schema Imports Microsoft.VisualBasic 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("UnknownAttributes.xml") End Sub Private Sub Serializer_UnknownAttribute _ (sender As Object , e As XmlAttributeEventArgs) Console.WriteLine("Unknown Attribute") Console.WriteLine(ControlChars.Tab & e.Attr.Name + " " & e.Attr.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.UnknownAttribute, _ AddressOf Serializer_UnknownAttribute ' 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
import System.*;
import System.IO.*;
import System.Xml.Serialization.*;
import System.Xml.*;
import System.Xml.Schema.*;
public class Group
{
public String groupName;
} //Group
public class Test
{
public static void main(String[] args)
{
Test t = new Test();
// Deserialize the file containing unknown elements.
t.DeserializeObject("UnknownAttributes.xml");
} //main
private void Serializer_UnknownAttribute(Object sender,
XmlAttributeEventArgs e)
{
Console.WriteLine("Unknown Attribute");
Console.WriteLine("\t" + e.get_Attr().get_Name() + " "
+ e.get_Attr().get_InnerXml());
Console.WriteLine("\t LineNumber: " + e.get_LineNumber());
Console.WriteLine("\t LinePosition: " + e.get_LinePosition());
Group x = (Group)e.get_ObjectBeingDeserialized();
Console.WriteLine(x.groupName);
Console.WriteLine(sender.ToString());
} //Serializer_UnknownAttribute
private void DeserializeObject(String filename)
{
XmlSerializer ser = new XmlSerializer(Group.class.ToType());
// Add a delegate to handle unknown element events.
ser.add_UnknownAttribute(new XmlAttributeEventHandler
(Serializer_UnknownAttribute));
// A FileStream is needed to read the XML document.
FileStream fs = new FileStream(filename, FileMode.Open);
Group g = (Group)ser.Deserialize(fs);
fs.Close();
} //DeserializeObject
} //Test
Windows 98, Windows 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
Reference
XmlSerializer ClassXmlSerializer Members
System.Xml.Serialization Namespace
XmlAnyAttributeAttribute Class
CanDeserialize
Deserialize
UnknownNode
XmlAttributes Class
Other Resources
Introducing XML SerializationHow to: Specify an Alternate Element Name for an XML Stream
Controlling XML Serialization Using Attributes
Examples of XML Serialization
XML Schema Definition Tool (Xsd.exe)