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XmlAttributes.XmlArrayItems Property

Gets or sets a collection of objects that specify how the XmlSerializer serializes items inserted into an array returned by a public field or read/write property.

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

Public ReadOnly Property XmlArrayItems As XmlArrayItemAttributes

Property Value

Type: System.Xml.Serialization.XmlArrayItemAttributes
An XmlArrayItemAttributes object that contains a collection of XmlArrayItemAttribute objects.

The XmlArrayItems property allows you to specify the derived types that can be inserted into an array returned by a public field or public read/write property. For each new type you want the field or property to accept, create an XmlArrayItemAttribute object and Add it to the XmlArrayItemAttributes) returned by the XmlArrayItems property. (The new type must be derived from the type already accepted by the field or property.) Add the XmlAttributes object to an XmlAttributeOverrides object and specify the type of the object that contains the field or property, and the name of the field or property. Construct an XmlSerializer with the XmlAttributeOverrides object before calling Serialize or Deserialize method.

The following example serializes a class that contains a field named Members that returns an array of objects. Two XmlArrayItemAttribute objects are created to allow the field to accept objects that derive from the base class named Member. Each object is added to the XmlAttributes through the XmlArrayItems property.

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

' This is the class that will be serialized.
Public Class Group
    Public Members() As Member
End Class

Public Class Member
    Public MemberName As String
End Class

Public Class NewMember
    Inherits Member
    Public MemberID As Integer
End Class

Public Class RetiredMember
    Inherits NewMember
    Public RetireDate As DateTime
End Class

Public Class Run

    Public Shared Sub Main()
        Dim test As New Run()
    End Sub    

    ' Return an XmlSerializer used for overriding. 
    Public Function CreateOverrider() As XmlSerializer
        ' Create XmlAttributeOverrides and XmlAttributes objects.
        Dim xOver As New XmlAttributeOverrides()
        Dim xAttrs As New XmlAttributes()

        ' Add an override for the XmlArrayItem.    
        Dim xArrayItem As New XmlArrayItemAttribute(GetType(NewMember))
        xArrayItem.Namespace = ""

        ' Add a second override.
        Dim xArrayItem2 As New XmlArrayItemAttribute(GetType(RetiredMember))
        xArrayItem2.Namespace = ""

        ' Add all overrides to XmlAttribueOverrides object.
        xOver.Add(GetType(Group), "Members", xAttrs)

        ' Create the XmlSerializer and return it.
        Return New XmlSerializer(GetType(Group), xOver)
    End Function 

    Public Sub SerializeObject(ByVal filename As String)
        ' Create an instance of the XmlSerializer class.
        Dim mySerializer As XmlSerializer = CreateOverrider()
        ' Writing the file requires a TextWriter.
        Dim writer As New StreamWriter(filename)

        ' Create an instance of the class that will be serialized.
        Dim myGroup As New Group()

        ' Set the object properties.
        Dim m As New NewMember()
        m.MemberName = "Paul"
        m.MemberID = 2

        ' Create a second member.
        Dim m2 As New RetiredMember()
        m2.MemberName = "Renaldo"
        m2.MemberID = 23
        m2.RetireDate = New DateTime(2000, 10, 10)

        myGroup.Members = New Member(1) {m, m2}

        ' Serialize the class, and close the TextWriter.
        mySerializer.Serialize(writer, myGroup)
    End Sub    

    Public Sub DeserializeObject(ByVal filename As String)
        Dim mySerializer As XmlSerializer = CreateOverrider()
        Dim fs As New FileStream(filename, FileMode.Open)
        Dim myGroup As Group = CType(mySerializer.Deserialize(fs), Group)
        Dim m As Member
        For Each m In  myGroup.Members
        Next m
    End Sub
End Class

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

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.