Custom Collection Property Persistence

[swalkertdci]

I have a composite control that I am working on that has a custom collection
property that is the type of another control. I believe I have all the
necessary atttributes set on the class and property (peristence,
parsechildren, etc...) but it still does not work properly. I can access the
property in the designer just fine and add new control instances, but when I
close the property window none of the controls I just created are persisted
into the HTML. To recreate the problem I created a very simple server control
that demonstrates the behavior. The code is as follows:

Imports System.Web
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.ComponentModel
Imports System.ComponentModel.Design
Imports System.Drawing

<ToolboxData("<{0}:ServerControlTest
runat=server></{0}:ServerControlTest>"), _
ParseChildren(True)> _
Public Class ServerControlTest
Inherits CompositeControl

Private moLabels As List(Of Label)

<Browsable(True), _
Category("Appearance"), _
Description("The ribbon groups for this tab."), _
PersistenceMode(PersistenceMode.InnerProperty), _

DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
Public ReadOnly Property Labels() As List(Of Label)
Get
Return moLabels
End Get
End Property

#Region "Rendering"
Protected Overrides Sub CreateChildControls()
MyBase.CreateChildControls()

Controls.Clear()
CreateControlHierarchy()
ClearChildViewState()
End Sub

Protected Sub CreateControlHierarchy()
Me.Width = Unit.Pixel(200)
Me.Height = Unit.Pixel(200)


' make sure we have controls to put in the content
If Not moLabels Is Nothing Then
For Each rb As Label In moLabels
Me.Controls.Add(rb)
Next
End If
End Sub


Protected Overrides ReadOnly Property TagKey() As
System.Web.UI.HtmlTextWriterTag
Get
Return HtmlTextWriterTag.Div
End Get
End Property
#End Region


End Class

If you try and use the "Labels" property in design mode you will see that
none of the labels added are properly persisted.

Can anyone please tell me why???