title: Usercontrol with a list type property is not updating
body: <p>I have written a VB.NET user control inheriting from a panel which is supposed to contain many buttons. My implementation has the buttons stored as a List(of Button). The bare bones code appears below. When I edit the control at design time, the collection editor opens properly, buttons are also added correctly but they do not appear in the control either at design time or run time. The form designer file shows that they are not added to the Controls collection of the panel. What am I doing wrong?</p>
  
  <pre><code>Imports System.ComponentModel
  Imports System.Collections
  
  Public Class ePanel
       Inherits Panel
  
  Private ButtonList As List(Of Button)
  
  
  &lt;DesignerSerializationVisibility(DesignerSerializationVisibility.Content), Description("Button list")&gt;
  Public Property Buttons As List(Of Button)
      Get
          Return (ButtonList)
      End Get
      Set(ByVal value As List(Of Button))
          ButtonList.Clear()
          ButtonList = value
          If (ButtonList.Count &gt; 0) Then
              For Each b As Button In ButtonList
                  Me.Controls.Add(b)
              Next
          End If
      End Set
  End Property
  
  
  
  Public Sub New()
  
      MyBase.BorderStyle = BorderStyle.FixedSingle
      MyBase.BackColor = Color.Bisque
  
      If (ButtonList.Count &gt; 0) Then
          For Each b As Button In ButtonList
              b.Dock = DockStyle.Top
              Me.Controls.Add(b)
          Next
      End If
  
  End Sub 
  End Class
  </code></pre>