Dim controlProperties As New ArrayList(3)

controlProperties.Add(SortDirection)
controlProperties.Add(SelectedColumn)
controlProperties.Add(CurrentPage.ToString())

' Create an ObjectStateFormatter to serialize the ArrayList.
Dim formatter As New ObjectStateFormatter()

' Call the Serialize method to serialize the ArrayList to a Base64 encoded string.
Dim base64StateString As String = formatter.Serialize(controlProperties)

'
' Persist any ViewState and ControlState.
'
Public Overrides Sub Save()

    If Not (ViewState Is Nothing) OrElse Not (ControlState Is Nothing) Then
        If Not (Page.Session Is Nothing) Then

            Dim stateStream As Stream
            stateStream = GetSecureStream()

            ' Write a state string, using the StateFormatter.
            Dim writer As New StreamWriter(stateStream)

            Dim formatter As IStateFormatter
            formatter = Me.StateFormatter

            Dim statePair As New Pair(ViewState, ControlState)

            Dim serializedState As String
            serializedState = formatter.Serialize(statePair)

            writer.Write(serializedState)
            writer.Close()
            stateStream.Close()
        Else
            Throw New InvalidOperationException("Session needed for StreamPageStatePersister.")
        End If
    End If
End Sub