XmlSerializer::UnknownElement Event
Occurs when the XmlSerializer encounters an XML element of unknown type during deserialization.
Assembly: System.Xml (in System.Xml.dll)
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.
Note |
|---|
If the XmlAnyElementAttribute is applied to a field that returns an array of XmlElement objects, all unknown elements are collected in the array. In that case, the UnknownElement event does not occur. |
The following example deserializes a class named Group from a file named UnknownElements.xml. Whenever an element is found in the file that has no corresponding member in the class, the UnknownElement event occurs. To try the example, paste the following XML code into a file named UnknownElements.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"> <GroupName>MyGroup</GroupName> <GroupSize>Large</GroupSize> <GroupNumber>444</GroupNumber> <GroupBase>West</GroupBase> </Group>
#using <System.Xml.dll> #using <System.dll> using namespace System; using namespace System::IO; using namespace System::Xml::Serialization; using namespace System::Xml; using namespace System::Xml::Schema; public ref class Group { public: String^ GroupName; }; public ref class Test { private: void Serializer_UnknownElement( Object^ sender, XmlElementEventArgs^ e ) { Console::WriteLine( "Unknown Element" ); Console::Write( "\t {0}", e->Element->Name ); Console::WriteLine( " {0}", e->Element->InnerXml ); Console::WriteLine( "\t LineNumber: {0}", e->LineNumber ); Console::WriteLine( "\t LinePosition: {0}", e->LinePosition ); Group^ x = dynamic_cast<Group^>(e->ObjectBeingDeserialized); Console::WriteLine( x->GroupName ); Console::WriteLine( sender ); } public: void DeserializeObject( String^ filename ) { XmlSerializer^ ser = gcnew XmlSerializer( Group::typeid ); // Add a delegate to handle unknown element events. ser->UnknownElement += gcnew XmlElementEventHandler( this, &Test::Serializer_UnknownElement ); // A FileStream is needed to read the XML document. FileStream^ fs = gcnew FileStream( filename,FileMode::Open ); Group^ g = dynamic_cast<Group^>(ser->Deserialize( fs )); fs->Close(); } }; int main() { Test^ t = gcnew Test; // Deserialize the file containing unknown elements. t->DeserializeObject( "UnknownElements.xml" ); }
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.
Note