Occurs when the System.Xml.Serialization.XmlSerializer encounters an XML element of unknown type during deserialization.
By default, after calling the XmlSerializer.Deserialize(System.IO.Stream) method, the System.Xml.Serialization.XmlSerializer ignores XML attributes of unknown types. However, you can use this event to handle such node types.
If the System.Xml.Serialization.XmlAnyElementAttribute is applied to a field that returns an array of System.Xml.XmlElement objects, all unknown elements are collected in the array. In that case, the XmlSerializer.UnknownElement event does not occur.