Save and Get values of Dynamically created controls from ViewState

Introduction

Firstly thanks to Paul Wilson whose articles have enlightened me about the ViewState Object.
This listing (an extract of Paul's article) explains events that take place in a client requested aspx page.

There are many programmers like me who would like to create dynamic controls
in a page on/after the Page_load event and still use the ViewState to store and
retrieve information about the controls value. Though the saving of information
is easy the retrieval part is not easy. By defining a functions in the PageClass
we can store and get information of all the dynamic controls that need to save
information in the ViewState object.

Using the code

Step 1: Create a page class

Public Class BasePage
      Inherits System.Web.UI.Page
 End Class

Step 2: Declare the following functions in this class 

Public Function SaveCtrlViewState(ByVal ID As String, ByVal value As Object)
    Me.ViewState(ID) = value
End Function 
  
Public Function GetCtrlViewState(ByVal ID As String) As Object
     Return Me.ViewState(ID)
End Function

Step 3: Create a WebControl Class

Public Class DynTextBox
    Inherits System.Web.UI.WebControls.TextBox
    Private _page as BasePage 
 
    Protected Overrides Sub OnInit(ByVal E As System.EventArgs)
    MyBase.OnInit(E)  
      _page = CType(Me.Page, BasePage)  
    End Sub
    Public Sub DoSomething()
       _page.SaveCtrlViewState(Me.ID, value)
    End Sub
    Public Sub DoSomethingMore()
       Dim oValue As Object = _page.GetCtrlViewState(Me.ID)
    End Sub
 
End Class

Step 4: Create a page that is derived from BasePage

Step 5: Create an instance of DynTextBox control in any event/Function (before Render)

in your Page

Step 6: Save the ViewState of the control by calling DoSomething function.

Step 7: Postback your page (have a Submit button)

Step 8: Create your control and call the function <DoSomethingMore> to get back the

control's ViewState

You finally have the flexibility to save your dynamic controls ViewState and get it back

without worrying much about the events that happen in your page.