CollectionDataContractAttribute Class


When applied to a collection type, enables custom specification of the collection item elements. This attribute can be applied only to types that are recognized by the DataContractSerializer as valid, serializable collections.

public ref class CollectionDataContractAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Struct, AllowMultiple=false, Inherited=false)]
public sealed class CollectionDataContractAttribute : Attribute
[<System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Struct, AllowMultiple=false, Inherited=false)>]
type CollectionDataContractAttribute = class
    inherit Attribute
Public NotInheritable Class CollectionDataContractAttribute
Inherits Attribute


The following example applies the CollectionDataContractAttribute to a class that inherits from the List<T> class. The code sets the Name and ItemName properties to custom values.

[CollectionDataContract(Name = "Custom{0}List", ItemName = "CustomItem")]
public class CustomList<T> : List<T>
    public CustomList()
        : base()

    public CustomList(T[] items)
        : base()
        foreach (T item in items)
<CollectionDataContract(Name := "Custom{0}List", ItemName := "CustomItem")> _
Public Class CustomList(Of T)
    Inherits List(Of T)
    Public Sub New()
    End Sub

    Public Sub New(ByVal items() As T)
        For Each item As T In items
        Next item
    End Sub
End Class

When the ServiceModel Metadata Utility Tool (Svcutil.exe) is used to generate code for the client, the code resembles the following example. Notice that the name of the class is changed, as well as the ItemName. When using generics, the type parameter name is used to create the resulting type name.

// This is the generated code. Note that the class is renamed to "CustomBookList",
// and the ItemName is set to "CustomItem".
[System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", "")]
[System.Runtime.Serialization.CollectionDataContractAttribute(ItemName = "CustomItem")]
public class CustomBookList : System.Collections.Generic.List<Microsoft.Security.Samples.Book>
' This is the generated code. Note that the class is renamed to "CustomBookList", 
' and the ItemName is set to "CustomItem".
<System.CodeDom.Compiler.GeneratedCodeAttribute("System.Runtime.Serialization", ""), System.Runtime.Serialization.CollectionDataContractAttribute(ItemName := "CustomItem")> _
Public Class CustomBookList
    Inherits System.Collections.Generic.List(Of Microsoft.Security.Samples.Book)
End Class


The CollectionDataContractAttribute is intended to ease interoperability when working with data from non-WCF providers and to control the exact shape of serialized instances. To this end, the ItemName property enables you to control the names of the repeating items inside a collection. This is especially useful when the provider does not use the XML element type name as the array item name, for example, if a provider uses "String" as an element type name instead of the XSD type name "string".

The CollectionDataContractAttribute is also intended to be used with dictionary types to handle keyed collections. Dictionary types are classes that implement either the IDictionary or the IDictionary<TKey,TValue> interface, for example, the Dictionary<TKey,TValue>. Use the KeyName and ValueName properties to set custom names when using the Dictionary<TKey,TValue> class.

For more information about using the DataContractSerializer, see Using Data Contracts.



Initializes a new instance of the CollectionDataContractAttribute class.



Gets whether ItemName has been explicitly set.


Gets whether KeyName has been explicitly set.


Gets whether Name has been explicitly set.


Gets whether Namespace has been explicitly set.


Gets or sets a value that indicates whether to preserve object reference data.


Gets whether reference has been explicitly set.


Gets whether ValueName has been explicitly set.


Gets or sets a custom name for a collection element.


Gets or sets the custom name for a dictionary key name.


Gets or sets the data contract name for the collection type.


Gets or sets the namespace for the data contract.


When implemented in a derived class, gets a unique identifier for this Attribute.

(Inherited from Attribute)

Gets or sets the custom name for a dictionary value name.



Returns a value that indicates whether this instance is equal to a specified object.

(Inherited from Attribute)

Returns the hash code for this instance.

(Inherited from Attribute)

Gets the Type of the current instance.

(Inherited from Object)

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(Inherited from Attribute)

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(Inherited from Attribute)

Creates a shallow copy of the current Object.

(Inherited from Object)

Returns a string that represents the current object.

(Inherited from Object)

Explicit Interface Implementations

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.

(Inherited from Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.

(Inherited from Attribute)

Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(Inherited from Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.

(Inherited from Attribute)

Applies to

See also