Problem with XML Serialzation of Collection of String

Question

Hello,
I am using the XML Serializer to create an XML Schema. In one part of the XML, I have an element called 'parameters', which returns a collection of strings that should be called 'parameter'. The output is supposed to look like this:

<parameters>
   <parameter>Value 1</parameter>
   <parameter>Value 2</parameter>
   <parameter>Value 3</parameter>
</parameters>

It's coming out like this:

<parameters>
   <string>Value 1</string>
   <string>Value 2</string>
   <string>Value 3</string>
</parameters>

My class code looks like this:

Public Class ParameterCollection
    Inherits System.Collections.ObjectModel.Collection(Of String)

    Public Sub New()
        MyBase.New()
    End Sub
    Public Overloads Sub Add(ByVal value As String)
        MyBase.Add(value)
    End Sub
    Default Public Overloads Property Item(ByVal index As Integer) As _
    <Xml.Serialization.XmlArrayItem(ElementName:="parameter", IsNullable:=True)> String
        Get
            Return MyBase.Item(index)
        End Get
        Set(ByVal value As String)
            If index <= Me.Count - 1 Then
                Me.Item(index) = value
            Else
                Throw New IndexOutOfRangeException()
            End If
        End Set
    End Property
    Public Overloads ReadOnly Property Count() As Integer
        Get
            Return MyBase.Count
        End Get
    End Property
    Public Overloads Sub Clear()
        MyBase.Clear()
    End Sub
    Public Overloads Sub RemoveAt(ByVal index As Integer)
        MyBase.RemoveAt(index)
    End Sub
End Class

I need the output to look exactly like my example at the top - I can't use an attribute, nor a subclass called 'parameter'. <br/>
The output does not come out right (at least from what I've tried).  I tried using different combinations of xmlserializer directives, <br/>
and I've tried an ArrayList in addition to the collection all with the same results. It seems as if the serializer is ignoring my directive<br/>
to call the element a 'parameter' and just calling it 'string'.<br/>
<br/>
I am using VB .Net 2005.<br/>
<br/>
Can anyone help?<br/>
<br/>
Thanks!<br/>
<br/>
Paul.<br/>

Answer 1

I think you want to put the XmlArrayItemAttribute on the class instead of on the Item property. 

Daniel Roth

---

ASMX, WCF

Answer 2

Hi, Daniel,Oh, I tried that!  I tried every combination I could think of.  It always comes out as 'string'.
-Paul

Answer 3

Hi again,
To further clarify, I cannot put the xmlArrayItemAttribute on the class definition because it is not allowed:
"Attribute 'XmlArrayAttribute' cannot be applied to 'ParameterCollection' because the attribute is not valid on this declaration type."

These are the types of things I've tried:

    <Xml.Serialization.XmlArrayItem("parameter")> _
    <Xml.Serialization.XmlElement("parameter")> _
    Default Public Overloads Property Item(ByVal index As Integer) As _
    <Xml.Serialization.XmlArrayItem(ElementName:="parameter", IsNullable:=True)> String
        Get
            Return MyBase.Item(index)
        End Get
        Set(ByVal value As String)
            If index <= Me.Count - 1 Then
                Me.Item(index) = value
            Else
                Throw New IndexOutOfRangeException()
            End If
        End Set
    End Property

-Paul

Answer 4

Hello, can anyone help with this?  I am still stuck! 
Thanks!

Paul

Answer 5

Have you tried implementing IXmlSerializable?

Answer 6

Is ParameterCollection the root of your document? If not, you can put the XmlArray and XmlArrayItem attributes on the property of type ParameterCollection; i.e:

<XmlArrayItem(ElementName:="parameter")>
Public Property Parameters As PropertyCollection

Answer 7

It worked!  It never occurred to me to put the directives on the higher-level class.  Once I did that it worked perfectly:

    <Xml.Serialization.XmlArrayItem(ElementName:="parameter")> _<br/>
    <Xml.Serialization.XmlArray("parameters")> _<br/>
    Public Property parameters() As ParameterCollection<br/>
        Get<br/>
            Return _parameters<br/>
        End Get<br/>
        Set(ByVal value As ParameterCollection)<br/>
            _parameters = value<br/>
        End Set<br/>
    End Property<br/>

Thanks to all for the assistance!
Paul