System.Xml.Serialization.XmlAttributeEventHandler Delegate

Summary

Represents the method that will handle the XmlSerializer.UnknownAttribute

C# Syntax:

[Serializable] public delegate void XmlAttributeEventHandler(object sender, XmlAttributeEventArgs e);

The declaration of your event handler must have the same parameters as the XmlAttributeEventHandler delegate declaration.

sender

The source of the event.

e

An XmlAttributeEventArgs that contains the event data.

When you create an XmlAttributeEventHandler delegate, you identify the method that will handle the event. To associate the event with your event handler, add an instance of the delegate to the event. The event handler is called whenever the event occurs, unless you remove the delegate. For more information about event handler delegates, see the conceptual topic at MSDN: eventsdelegates.

The XmlSerializer.UnknownAttribute event occurs only when an object is being deserialized with the XmlSerializer.Deserialize method.

The following example deserializes a class named Group from a file named UnknownAttributes.xml. Whenever an element is found in the file that has no corresponding member in the class, the XmlSerializer.UnknownAttribute event occurs. To try the example, paste the XML code below into a file named UnknownAttributes.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" GroupType = 'Technical' GroupNumber = '42' GroupBase = 'Red'>
            <GroupName>MyGroup</GroupName>
          </Group>
        

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("UnknownAttributes.xml");
   }
   private void Serializer_UnknownAttribute(object sender, XmlAttributeEventArgs e){
      Console.WriteLine("Unknown Attribute");
      Console.WriteLine("\t" + e.Attr.Name + " " + e.Attr.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.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();
   	}
}

    

System.Xml.Serialization Namespace | XmlNodeEventHandler | XmlSerializer.Deserialize | XmlSerializer

Hierarchy:

• System.Object
• System.Delegate
• System.MulticastDelegate
• System.Xml.Serialization.XmlAttributeEventHandler

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