XmlElementEventHandler Delegate
Represents the method that handles the UnknownElement event of an XmlSerializer.
Assembly: System.Xml (in System.Xml.dll)
Parameters
- sender
- Type: System::Object
The source of the event.
- e
- Type: System.Xml.Serialization::XmlElementEventArgs
A XmlElementEventArgs that contains the event data.
When you create an XmlElementEventHandler delegate, you identify the method that handles 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 Events and Delegates.
The UnknownElement event occurs only when you call the Deserialize method.
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.