XmlAttributeOverrides::Add Method (Type^, XmlAttributes^)

 

Adds an XmlAttributes object to the collection of XmlAttributes objects. The type parameter specifies an object to be overridden by the XmlAttributes object.

Namespace:   System.Xml.Serialization
Assembly:  System.Xml (in System.Xml.dll)

public:
void Add(
	Type^ type,
	XmlAttributes^ attributes
)

Parameters

type
Type: System::Type^

The Type of the object that is overridden.

attributes
Type: System.Xml.Serialization::XmlAttributes^

An XmlAttributes object that represents the overriding attributes.

The XmlAttributes object contains a union of attribute objects that cause the XmlSerializer to override its default serialization behavior for a set of objects. You choose the attribute objects to place in the XmlAttributes object, depending on the particular behaviors you want to override. For example, the XmlSerializer serializes a class member as an XML element by default. If you want the member to be serialized as an XM attribute instead, you would create an XmlAttributeAttribute, assign it to the XmlAttribute property of an XmlAttributes, and add the XmlAttributes object to the XmlAttributeOverrides object.

Use this overload to override an XmlRootAttribute or XmlTypeAttribute.

The following example serializes a class named Band which is derived from a class named Orchestra. The example creates an XmlRootAttribute object, and assigns it to the XmlRoot property of an XmlAttributes object. The example then calls the Add method to add the XmlAttributes object to the XmlAttributeOverrides object.

#using <System.Xml.dll>
#using <System.dll>

using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;

ref class Band;
ref class Instrument;

/* This is the class that will be overridden. The XmlIncludeAttribute 
tells the XmlSerializer that the overriding type exists. */

[XmlInclude(Band::typeid)]
public ref class Orchestra
{
public:
   array<Instrument^>^Instruments;
};

// This is the overriding class.
public ref class Band: public Orchestra
{
public:
   String^ BandName;
};

public ref class Instrument
{
public:
   String^ Name;
};

void SerializeObject( String^ filename )
{
   /* Each object that is being overridden requires 
      an XmlAttributes object. */
   XmlAttributes^ attrs = gcnew XmlAttributes;

   // An XmlRootAttribute allows overriding the Orchestra class.
   XmlRootAttribute^ xmlRoot = gcnew XmlRootAttribute;

   // Set the object to the XmlAttribute.XmlRoot property.
   attrs->XmlRoot = xmlRoot;

   // Create an XmlAttributeOverrides object.
   XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;

   // Add the XmlAttributes to the XmlAttributeOverrrides.
   attrOverrides->Add( Orchestra::typeid, attrs );

   // Create the XmlSerializer using the XmlAttributeOverrides.
   XmlSerializer^ s = gcnew XmlSerializer( Orchestra::typeid,attrOverrides );

   // Writing the file requires a TextWriter.
   TextWriter^ writer = gcnew StreamWriter( filename );

   // Create the object using the derived class.
   Band^ band = gcnew Band;
   band->BandName = "NewBand";

   // Create an Instrument.
   Instrument^ i = gcnew Instrument;
   i->Name = "Trumpet";
   array<Instrument^>^myInstruments = {i};
   band->Instruments = myInstruments;

   // Serialize the object.
   s->Serialize( writer, band );
   writer->Close();
}

void DeserializeObject( String^ filename )
{
   XmlAttributes^ attrs = gcnew XmlAttributes;
   XmlRootAttribute^ attr = gcnew XmlRootAttribute;
   attrs->XmlRoot = attr;
   XmlAttributeOverrides^ attrOverrides = gcnew XmlAttributeOverrides;
   attrOverrides->Add( Orchestra::typeid, "Instruments", attrs );
   XmlSerializer^ s = gcnew XmlSerializer( Orchestra::typeid,attrOverrides );
   FileStream^ fs = gcnew FileStream( filename,FileMode::Open );

   // Deserialize the Band object.
   Band^ band = dynamic_cast<Band^>(s->Deserialize( fs ));
   Console::WriteLine( "Brass:" );
   System::Collections::IEnumerator^ myEnum = band->Instruments->GetEnumerator();
   while ( myEnum->MoveNext() )
   {
      Instrument^ i = safe_cast<Instrument^>(myEnum->Current);
      Console::WriteLine( i->Name );
   }
}

int main()
{
   SerializeObject( "Override.xml" );
   DeserializeObject( "Override.xml" );
}

Universal Windows Platform
Available since 8
.NET Framework
Available since 1.1
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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