Hello Everybody,

I have a collection that I an trying to serialize, but when I try to I get the following error message:

The type SerializationExample02.User was not expected. Use the XmlInclude or SoapInclude attribute to specify types that are not known statically.

Here is the code that I use to build my collection of classes:

    Private Sub Button4_Click(sender As Object, e As EventArgs) Handles Button4.Click

        Try

            Dim oUserA As New User
            Dim oUserB As New User
            Dim oUserC As New User
            Dim oUserD As New User

            Dim oUsers06 As New Users06

            With oUserA
                .UserID = "A"
                .UserName = "A Name"
                .UserAccessLevel = 4
                .UserPassword = "A's Secret Password"
                oUsers06.Add(oUserA)
            End With

            With oUserB
                .UserID = "B"
                .UserName = "B Name"
                .UserAccessLevel = 4
                .UserPassword = "B's Secret Password"
                oUsers06.Add(oUserB)
            End With

            With oUserC
                .UserID = "C"
                .UserName = "C Name"
                .UserAccessLevel = 4
                .UserPassword = "C's Secret Password"
                oUsers06.Add(oUserC)
            End With

            With oUserD
                .UserID = "D"
                .UserName = "D Name"
                .UserAccessLevel = 4
                .UserPassword = "D's Secret Password"
                oUsers06.Add(oUserD)
            End With

            'Dim oWriter As TextWriter = New StreamWriter("C:\Users\Gary Hagerty\Documents\Visual Studio 2012\Projects\SerializationExample02\SerializationExample02\Users.XML")
            Dim oWriter As New StreamWriter("C:\Users\Gary Hagerty\Documents\Visual Studio 2012\Projects\SerializationExample02\SerializationExample02\Users06.XML")
            Dim oXMLSerialize As New XmlSerializer(GetType(Users06))

            oXMLSerialize.Serialize(oWriter, oUsers06)

            oWriter.Close()

        Catch oError As Exception

            Dim sErrorString As String
            sErrorString = "Message ---" & oError.Message
            sErrorString = sErrorString & vbCrLf
            sErrorString = sErrorString & "HelpLink ---" & oError.HelpLink
            sErrorString = sErrorString & vbCrLf
            sErrorString = sErrorString & "Source ---" & oError.Source
            sErrorString = sErrorString & vbCrLf
            sErrorString = sErrorString & "StackTrace ---" & oError.StackTrace
            sErrorString = sErrorString & vbCrLf
            sErrorString = sErrorString & "TargetSite ---" & oError.TargetSite.ToString
            MessageBox.Show(sErrorString, "Error")

            End

        End Try

    End Sub

 The code for my collection is as follows:

Public Class Users06

    Implements IList

    Private moArray As ArrayList = New ArrayList()

    Public Sub CopyTo(ByVal array As Array, _
                      ByVal index As Integer) Implements ICollection.CopyTo

        moArray.CopyTo(array, index)

    End Sub

    Public ReadOnly Property Count As Integer Implements ICollection.Count

        Get
            Count = moArray.Count
        End Get

    End Property

    Public ReadOnly Property IsSynchronized As Boolean Implements ICollection.IsSynchronized

        Get
            Return False
        End Get

    End Property

    Public ReadOnly Property SyncRoot As Object Implements ICollection.SyncRoot

        Get
            Return Me
        End Get

    End Property

    Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator

        Return moArray.GetEnumerator()

    End Function

    Public Function Add(ByVal oUser As Object) As Integer Implements IList.Add

        moArray.Add(oUser)
        Return moArray.Count

    End Function

    Public Sub Clear() Implements IList.Clear

        moArray.Clear()

    End Sub

    Public Function Contains(ByVal oUser As Object) As Boolean Implements IList.Contains

        Contains = moArray.Contains(oUser)

    End Function

    Public Function IndexOf(ByVal oUser As Object) As Integer Implements IList.IndexOf

        IndexOf = moArray.IndexOf(oUser)

    End Function

    Public Sub Insert(ByVal iIndex As Integer, _
                      ByVal oUser As Object) Implements IList.Insert

        moArray.Insert(iIndex, oUser)

    End Sub

    Public ReadOnly Property IsFixedSize As Boolean Implements IList.IsFixedSize

        Get
            Return False
        End Get

    End Property

    Public ReadOnly Property IsReadOnly As Boolean Implements IList.IsReadOnly

        Get
            Return False
        End Get

    End Property

    Default Public Property Item(ByVal iIndex As Integer) As Object Implements IList.Item

        Get
            Return CType(moArray.Item(iIndex), User)
        End Get

        Set(oUser As Object)
            moArray.Item(iIndex) = oUser
        End Set

    End Property

    Public Sub Remove(ByVal oUser As Object) Implements IList.Remove

        moArray.Remove(oUser)

    End Sub

    Public Sub RemoveAt(ByVal iIndex As Integer) Implements IList.RemoveAt

        moArray.RemoveAt(iIndex)

    End Sub

End Class

The code for my class is as follows:

Serializable() _
Public Class User

    Private miUserAccessLevel As Integer

    Private msUserID As String
    Private msUserName As String
    Private msUserPassword As String

    Public Property UserID() As String
        Get
            Return msUserID
        End Get
        Set(value As String)
            msUserID = value
        End Set
    End Property

    Public Property UserName() As String
        Get
            Return msUserName
        End Get
        Set(value As String)
            msUserName = value
        End Set
    End Property

    Public Property UserPassword() As String
        Get
            Return msUserPassword
        End Get
        Set(value As String)
            msUserPassword = value
        End Set
    End Property

    'Public Property UserLoggedIn() As Boolean
    '    Get
    '        Return mbUserLoggedIn
    '    End Get
    '    Set(value As Boolean)
    '        mbUserLoggedIn = value
    '    End Set
    'End Property

    Public Property UserAccessLevel() As Integer
        Get
            Return miUserAccessLevel
        End Get
        Set(value As Integer)
            miUserAccessLevel = value
        End Set
    End Property

End Class

Please advise

Thank you

Gary