XmlElementAttributes Class

Definition

Namespace:

System.Xml.Serialization

Assembly:

System.Xml.XmlSerializer.dll

Source:

XmlElementAttributes.cs

Represents a collection of XmlElementAttribute objects used by the XmlSerializer to override the default way it serializes a class.

public ref class XmlElementAttributes : System::Collections::CollectionBase

public class XmlElementAttributes : System.Collections.CollectionBase

type XmlElementAttributes = class
    inherit CollectionBase

Public Class XmlElementAttributes
Inherits CollectionBase

Inheritance

Object

CollectionBase

XmlElementAttributes

Examples

The following example serializes the Transportation class, which contains a single field named Vehicles that returns an ArrayList. The example first applies two instances of the XmlElementAttribute class to the Vehicles field that specifies the types of objects the XmlSerializer inserts into the array. The example then creates two XmlElementAttribute objects to override the behavior of the attributes applied to the Vehicles property. The two overriding objects are added to the XmlElementAttributes collection of an XmlAttributes. Lastly, the example adds the XmlAttributes to an XmlAttributeOverrides, allowing the XmlSerializer to insert the new object types into the ArrayList returned by the Vehicles field.

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

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

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

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

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

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

public ref class Transportation
{
public:

   // Override these two XmlElementAttributes.

   [XmlElement(Car::typeid),
   XmlElement(Plane::typeid)]
   ArrayList^ Vehicles;
};

XmlSerializer^ CreateOverrider()
{
   // Create XmlAtrributes and XmlAttributeOverrides instances. 
   XmlAttributes^ attrs = gcnew XmlAttributes;
   XmlAttributeOverrides^ xOver = gcnew XmlAttributeOverrides;

   /* Create an XmlElementAttributes object to override 
      one of the attributes applied to the Vehicles property. */
   XmlElementAttribute^ xElement1 = gcnew XmlElementAttribute( Truck::typeid );

   // Add the XmlElementAttribute to the collection.
   attrs->XmlElements->Add( xElement1 );

   /* Create a second XmlElementAttribute and 
      add it to the collection. */
   XmlElementAttribute^ xElement2 = gcnew XmlElementAttribute( Train::typeid );
   attrs->XmlElements->Add( xElement2 );

   /* Add the XmlAttributes to the XmlAttributeOverrides,
      specifying the member to override. */
   xOver->Add( Transportation::typeid, "Vehicles", attrs );

   // Create the XmlSerializer, and return it.
   XmlSerializer^ xSer = gcnew XmlSerializer( Transportation::typeid,xOver );
   return xSer;
}

void SerializeObject( String^ filename )
{
   // Create an XmlSerializer instance.
   XmlSerializer^ xSer = CreateOverrider();

   // Create the object.
   Transportation^ myTransportation = gcnew Transportation;

   /* Create two new, overriding objects that can be
      inserted into the Vehicles array. */
   myTransportation->Vehicles = gcnew ArrayList;
   Truck^ myTruck = gcnew Truck;
   myTruck->Name = "MyTruck";
   Train^ myTrain = gcnew Train;
   myTrain->Name = "MyTrain";
   myTransportation->Vehicles->Add( myTruck );
   myTransportation->Vehicles->Add( myTrain );
   TextWriter^ writer = gcnew StreamWriter( filename );
   xSer->Serialize( writer, myTransportation );
}

int main()
{
   SerializeObject( "OverrideElement.xml" );
}

using System;
using System.IO;
using System.Xml.Serialization;
using System.Collections;
using System.Xml;

public class Transportation
{
   // Override these two XmlElementAttributes.
   [XmlElement(typeof(Car)),
   XmlElement(typeof(Plane))]
   public ArrayList Vehicles;
}

public class Car
{
   public string Name;
}

public class Plane
{
   public string Name;
}

public class Truck
{
   public string Name;
}

public class Train
{
   public string Name;
}

public class Test
{
   public static void Main()
   {
      Test t = new Test();
      t.SerializeObject("OverrideElement.xml");
   }

   public XmlSerializer CreateOverrider()
   {
      // Create XmlAtrributes and XmlAttributeOverrides instances.

      XmlAttributes attrs = new XmlAttributes();

      XmlAttributeOverrides xOver =
      new XmlAttributeOverrides();

      /* Create an XmlElementAttributes object to override
      one of the attributes applied to the Vehicles property. */
      XmlElementAttribute xElement1 =
      new XmlElementAttribute(typeof(Truck));
      // Add the XmlElementAttribute to the collection.
      attrs.XmlElements.Add(xElement1);

      /* Create a second XmlElementAttribute and
      add it to the collection. */
      XmlElementAttribute xElement2 =
      new XmlElementAttribute(typeof(Train));
      attrs.XmlElements.Add(xElement2);

      /* Add the XmlAttributes to the XmlAttributeOverrides,
      specifying the member to override. */
      xOver.Add(typeof(Transportation), "Vehicles", attrs);

      // Create the XmlSerializer, and return it.
      XmlSerializer xSer = new XmlSerializer
      (typeof(Transportation), xOver);
      return xSer;
   }

   public void SerializeObject(string filename)
   {
      // Create an XmlSerializer instance.
      XmlSerializer xSer = CreateOverrider();

      // Create the object.
      Transportation myTransportation =
      new Transportation();

      /* Create two new, overriding objects that can be
      inserted into the Vehicles array. */
      myTransportation.Vehicles = new ArrayList();
      Truck myTruck = new Truck();
      myTruck.Name = "MyTruck";

      Train myTrain = new Train();
      myTrain.Name = "MyTrain";

      myTransportation.Vehicles.Add(myTruck);
      myTransportation.Vehicles.Add(myTrain);

      TextWriter writer = new StreamWriter(filename);
      xSer.Serialize(writer, myTransportation);
   }
}

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


Public Class Transportation
    ' Override these two XmlElementAttributes.
    <XmlElement(GetType(Car)), _
     XmlElement(GetType(Plane))> _
    Public Vehicles As ArrayList
End Class

Public Class Car
    Public Name As String
End Class

Public Class Plane
    Public Name As String
End Class

Public Class Truck
    Public Name As String
End Class

Public Class Train
    Public Name As String
End Class

Public Class Test
    
    Public Shared Sub Main()
        Dim t As New Test()
        t.SerializeObject("OverrideElement.xml")
    End Sub
    
    
    Public Function CreateOverrider() As XmlSerializer
        ' Create XmlAtrributes and XmlAttributeOverrides instances. 
        Dim attrs As New XmlAttributes()
        
        Dim xOver As New XmlAttributeOverrides()
        
        ' Create an XmlElementAttributes object to override
        ' one of the attributes applied to the Vehicles property. 
        Dim xElement1 As New XmlElementAttribute(GetType(Truck))
        ' Add the XmlElementAttribute to the collection.
        attrs.XmlElements.Add(xElement1)
        
        ' Create a second XmlElementAttribute and
        ' add it to the collection. 
        Dim xElement2 As New XmlElementAttribute(GetType(Train))
        attrs.XmlElements.Add(xElement2)
        
        ' Add the XmlAttributes to the XmlAttributeOverrides,
        ' specifying the member to override. 
        xOver.Add(GetType(Transportation), "Vehicles", attrs)
        
        ' Create the XmlSerializer, and return it.
        Dim xSer As New XmlSerializer(GetType(Transportation), xOver)
        Return xSer
    End Function
    
    
    Public Sub SerializeObject(ByVal filename As String)
        ' Create an XmlSerializer instance.
        Dim xSer As XmlSerializer = CreateOverrider()
        
        ' Create the object.
        Dim myTransportation As New Transportation()
        
        ' Create two new, overriding objects that can be
        ' inserted into the Vehicles array. 
        myTransportation.Vehicles = New ArrayList()
        Dim myTruck As New Truck()
        myTruck.Name = "MyTruck"
        
        Dim myTrain As New Train()
        myTrain.Name = "MyTrain"
        
        myTransportation.Vehicles.Add(myTruck)
        myTransportation.Vehicles.Add(myTrain)
        
        Dim writer As New StreamWriter(filename)
        xSer.Serialize(writer, myTransportation)
    End Sub
End Class

Remarks

The XmlElementAttributes is returned by the XmlElements property of the XmlAttributes class. By using the XmlAttributeOverrides class and the XmlAttributes class, you can override the default way that the XmlSerializer serializes a class.

Constructors

XmlElementAttributes()

Initializes a new instance of the XmlElementAttributes class.

Properties

Capacity	Gets or sets the number of elements that the CollectionBase can contain. (Inherited from CollectionBase)
Count	Gets the number of elements contained in the CollectionBase instance. This property cannot be overridden. (Inherited from CollectionBase)
InnerList	Gets an ArrayList containing the list of elements in the CollectionBase instance. (Inherited from CollectionBase)
Item[Int32]	Gets or sets the element at the specified index.
List	Gets an IList containing the list of elements in the CollectionBase instance. (Inherited from CollectionBase)

Methods

Add(XmlElementAttribute)	Adds an XmlElementAttribute to the collection.
Clear()	Removes all objects from the CollectionBase instance. This method cannot be overridden. (Inherited from CollectionBase)
Contains(XmlElementAttribute)	Determines whether the collection contains the specified object.
CopyTo(XmlElementAttribute[], Int32)	Copies the XmlElementAttributes, or a portion of it to a one-dimensional array.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetEnumerator()	Returns an enumerator that iterates through the CollectionBase instance. (Inherited from CollectionBase)
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
IndexOf(XmlElementAttribute)	Gets the index of the specified XmlElementAttribute.
Insert(Int32, XmlElementAttribute)	Inserts an XmlElementAttribute into the collection.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
OnClear()	Performs additional custom processes when clearing the contents of the CollectionBase instance. (Inherited from CollectionBase)
OnClearComplete()	Performs additional custom processes after clearing the contents of the CollectionBase instance. (Inherited from CollectionBase)
OnInsert(Int32, Object)	Performs additional custom processes before inserting a new element into the CollectionBase instance. (Inherited from CollectionBase)
OnInsertComplete(Int32, Object)	Performs additional custom processes after inserting a new element into the CollectionBase instance. (Inherited from CollectionBase)
OnRemove(Int32, Object)	Performs additional custom processes when removing an element from the CollectionBase instance. (Inherited from CollectionBase)
OnRemoveComplete(Int32, Object)	Performs additional custom processes after removing an element from the CollectionBase instance. (Inherited from CollectionBase)
OnSet(Int32, Object, Object)	Performs additional custom processes before setting a value in the CollectionBase instance. (Inherited from CollectionBase)
OnSetComplete(Int32, Object, Object)	Performs additional custom processes after setting a value in the CollectionBase instance. (Inherited from CollectionBase)
OnValidate(Object)	Performs additional custom processes when validating a value. (Inherited from CollectionBase)
Remove(XmlElementAttribute)	Removes the specified object from the collection.
RemoveAt(Int32)	Removes the element at the specified index of the CollectionBase instance. This method is not overridable. (Inherited from CollectionBase)
ToString()	Returns a string that represents the current object. (Inherited from Object)

Explicit Interface Implementations

ICollection.CopyTo(Array, Int32)	Copies the entire CollectionBase to a compatible one-dimensional Array, starting at the specified index of the target array. (Inherited from CollectionBase)
ICollection.IsSynchronized	Gets a value indicating whether access to the CollectionBase is synchronized (thread safe). (Inherited from CollectionBase)
ICollection.SyncRoot	Gets an object that can be used to synchronize access to the CollectionBase. (Inherited from CollectionBase)
IList.Add(Object)	Adds an object to the end of the CollectionBase. (Inherited from CollectionBase)
IList.Contains(Object)	Determines whether the CollectionBase contains a specific element. (Inherited from CollectionBase)
IList.IndexOf(Object)	Searches for the specified Object and returns the zero-based index of the first occurrence within the entire CollectionBase. (Inherited from CollectionBase)
IList.Insert(Int32, Object)	Inserts an element into the CollectionBase at the specified index. (Inherited from CollectionBase)
IList.IsFixedSize	Gets a value indicating whether the CollectionBase has a fixed size. (Inherited from CollectionBase)
IList.IsReadOnly	Gets a value indicating whether the CollectionBase is read-only. (Inherited from CollectionBase)
IList.Item[Int32]	Gets or sets the element at the specified index. (Inherited from CollectionBase)
IList.Remove(Object)	Removes the first occurrence of a specific object from the CollectionBase. (Inherited from CollectionBase)

Extension Methods

Cast<TResult>(IEnumerable)	Casts the elements of an IEnumerable to the specified type.
OfType<TResult>(IEnumerable)	Filters the elements of an IEnumerable based on a specified type.
AsParallel(IEnumerable)	Enables parallelization of a query.
AsQueryable(IEnumerable)	Converts an IEnumerable to an IQueryable.

See also

• XmlAttributes
• Introducing XML Serialization
• How to: Specify an Alternate Element Name for an XML Stream
• Controlling XML Serialization Using Attributes
• Examples of XML Serialization
• XML Schema Definition Tool (Xsd.exe)