Export (0) Print
Expand All

XmlAttributeOverrides.Add Method (Type, XmlAttributes)

.NET Framework 1.1

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

[Visual Basic]
Overloads Public Sub Add( _
   ByVal type As Type, _
   ByVal attributes As XmlAttributes _
)
[C#]
public void Add(
 Type type,
 XmlAttributes attributes
);
[C++]
public: void Add(
 Type* type,
 XmlAttributes* attributes
);
[JScript]
public function Add(
   type : Type,
 attributes : XmlAttributes
);

Parameters

type
The Type of the object that will be overridden.
attributes
An XmlAttributes object that represents the overriding attributes.

Remarks

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 XmlAttribute 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 to override an XmlRootAttribute or XmlTypeAttribute.

Example

[Visual Basic, C#, C++] 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.

[Visual Basic] 
Option Explicit
Option Strict

Imports System
Imports System.IO
Imports System.Xml.Serialization


' This is the class that will be overridden. The XmlIncludeAttribute
' tells the XmlSerializer that the overriding type exists. 
<XmlInclude(GetType(Band))> _
Public Class Orchestra
    Public Instruments() As Instrument
End Class

' This is the overriding class.
Public Class Band
    Inherits Orchestra
    Public BandName As String
End Class

Public Class Instrument
    Public Name As String
End Class

Public Class Run
    
    Public Shared Sub Main()
        Dim test As New Run()
        test.SerializeObject("Override.xml")
        test.DeserializeObject("Override.xml")
    End Sub    
    
    Public Sub SerializeObject(ByVal filename As String)
        ' Each object that is being overridden requires
        ' an XmlAttributes object. 
        Dim attrs As New XmlAttributes()
        
        ' An XmlRootAttribute allows overriding the Orchestra class.
        Dim xmlRoot As New XmlRootAttribute()
        
        ' Set the object to the XmlAttribute.XmlRoot property.
        attrs.XmlRoot = xmlRoot
        
        ' Create an XmlAttributeOverrides object.
        Dim attrOverrides As New XmlAttributeOverrides()
        
        ' Add the XmlAttributes to the XmlAttributeOverrrides.
        attrOverrides.Add(GetType(Orchestra), attrs)
        
        ' Create the XmlSerializer using the XmlAttributeOverrides.
        Dim s As New XmlSerializer(GetType(Orchestra), attrOverrides)
        
        ' Writing the file requires a TextWriter.
        Dim writer As New StreamWriter(filename)
        
        ' Create the object using the derived class.
        Dim band As New Band()
        band.BandName = "NewBand"
        
        ' Create an Instrument.
        Dim i As New Instrument()
        i.Name = "Trumpet"
        Dim myInstruments() As Instrument = {i}
        band.Instruments = myInstruments
        
        ' Serialize the object.
        s.Serialize(writer, band)
        writer.Close()
    End Sub    
    
    Public Sub DeserializeObject(ByVal filename As String)
        Dim attrs As New XmlAttributes()
        Dim attr As New XmlRootAttribute()
        attrs.XmlRoot = attr
        Dim attrOverrides As New XmlAttributeOverrides()
        
        attrOverrides.Add(GetType(Orchestra), "Instruments", attrs)
        
        Dim s As New XmlSerializer(GetType(Orchestra), attrOverrides)
        
        Dim fs As New FileStream(filename, FileMode.Open)
        
        ' Deserialize the Band object.
        Dim band As Band = CType(s.Deserialize(fs), Band)
        Console.WriteLine("Brass:")
        
        Dim i As Instrument
        For Each i In  band.Instruments
            Console.WriteLine(i.Name)
        Next i
    End Sub
End Class


[C#] 
using System;
using System.IO;
using System.Xml.Serialization;

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

[XmlInclude(typeof(Band))]
public class Orchestra
{
   public Instrument[] Instruments;
}   

// This is the overriding class.
public class Band:Orchestra
{
   public string BandName;
}

public class Instrument
{
   public string Name;
}

public class Run
{
    public static void Main()
    {
       Run test = new Run();
       test.SerializeObject("Override.xml");
       test.DeserializeObject("Override.xml");
    }


    public void SerializeObject(string filename)
    {
      /* Each object that is being overridden requires 
      an XmlAttributes object. */
      XmlAttributes attrs = new XmlAttributes();

      // An XmlRootAttribute allows overriding the Orchestra class.
      XmlRootAttribute xmlRoot = new XmlRootAttribute();

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

      // Create an XmlAttributeOverrides object.
      XmlAttributeOverrides attrOverrides = 
      new XmlAttributeOverrides();

      // Add the XmlAttributes to the XmlAttributeOverrrides.
      attrOverrides.Add(typeof(Orchestra), attrs);

      // Create the XmlSerializer using the XmlAttributeOverrides.
      XmlSerializer s = 
      new XmlSerializer(typeof(Orchestra), attrOverrides);

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

      // Create the object using the derived class.
      Band band = new Band();
      band.BandName = "NewBand";

      // Create an Instrument.
      Instrument i = new Instrument();
      i.Name = "Trumpet";
      Instrument[] myInstruments = {i};
      band.Instruments = myInstruments;

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

   public void DeserializeObject(string filename)
   {
      XmlAttributes attrs = new XmlAttributes();
      XmlRootAttribute attr = new XmlRootAttribute();
      attrs.XmlRoot = attr;
      XmlAttributeOverrides attrOverrides = 
         new XmlAttributeOverrides();

      attrOverrides.Add(typeof(Orchestra), "Instruments", attrs);

      XmlSerializer s = 
      new XmlSerializer(typeof(Orchestra), attrOverrides);

      FileStream fs = new FileStream(filename, FileMode.Open);

      // Deserialize the Band object.
      Band band = (Band) s.Deserialize(fs);
      Console.WriteLine("Brass:");

      foreach(Instrument i in band.Instruments) 
      {
         Console.WriteLine(i.Name);
      }
   }
}


[C++] 
#using <mscorlib.dll>
#using <System.Xml.dll>
#using <System.dll>
using namespace System;
using namespace System::IO;
using namespace System::Xml::Serialization;

public __gc class Band;
public __gc class Instrument;

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

[XmlInclude(__typeof(Band))]
public __gc class Orchestra
{
public:
   Instrument* Instruments[];
};   

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

public __gc class Instrument
{
public:
   String* Name;
};

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

   // An XmlRootAttribute allows overriding the Orchestra class.
   XmlRootAttribute* xmlRoot = new XmlRootAttribute();

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

   // Create an XmlAttributeOverrides object.
   XmlAttributeOverrides* attrOverrides = 
      new XmlAttributeOverrides();

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

   // Create the XmlSerializer using the XmlAttributeOverrides.
   XmlSerializer* s = 
      new XmlSerializer(__typeof(Orchestra), attrOverrides);

   // Writing the file requires a TextWriter.
   TextWriter* writer = new StreamWriter(filename);

   // Create the object using the derived class.
   Band* band = new Band();
   band->BandName = S"NewBand";

   // Create an Instrument.
   Instrument* i = new Instrument();
   i->Name = S"Trumpet";
   Instrument* myInstruments[] = {i};
   band->Instruments = myInstruments;

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

void DeserializeObject(String* filename)
{
   XmlAttributes* attrs = new XmlAttributes();
   XmlRootAttribute* attr = new XmlRootAttribute();
   attrs->XmlRoot = attr;
   XmlAttributeOverrides* attrOverrides = 
      new XmlAttributeOverrides();

   attrOverrides->Add(__typeof(Orchestra), S"Instruments", attrs);

   XmlSerializer* s = 
      new XmlSerializer(__typeof(Orchestra), attrOverrides);

   FileStream* fs = new FileStream(filename, FileMode::Open);

   // Deserialize the Band object.
   Band* band = dynamic_cast<Band*> (s->Deserialize(fs));
   Console::WriteLine(S"Brass:");

   System::Collections::IEnumerator* myEnum = band->Instruments->GetEnumerator();
   while (myEnum->MoveNext())
   {
      Instrument* i = __try_cast<Instrument*>(myEnum->Current);
      Console::WriteLine(i->Name);
   }
}

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

[JScript] No example is available for JScript. To view a Visual Basic, C#, or C++ example, click the Language Filter button Language Filter in the upper-left corner of the page.

Requirements

Platforms: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 family

See Also

XmlAttributeOverrides Class | XmlAttributeOverrides Members | System.Xml.Serialization Namespace | XmlAttributeOverrides.Add Overload List | XmlAttributes | XmlSerializer

Show:
© 2015 Microsoft