Access Objects Created By Another VB Script - asp.net

Question

I have a gridview that has textboxes where the user can type text to filter results. The textboxes are created dynamically by an extender below:
Imports Microsoft.VisualBasic
Namespace ControlExtenders
Partial Public Class GridView : Inherits System.Web.UI.WebControls.GridView
' METHOD:: OnLoad
Protected Overrides Sub OnLoad(ByVal e As EventArgs)
MyBase.OnLoad(e)
Me.SetPageSize()
End Sub
Protected Overloads Overrides Sub InitializeRow(ByVal row As GridViewRow, ByVal fields As DataControlField())
MyBase.InitializeRow(row, fields)
If row.RowType = DataControlRowType.Header Then
InitializeHeaderRow(row, fields)
End If
End Sub
Protected Overridable Sub InitializeHeaderRow(ByVal row As GridViewRow, ByVal fields As DataControlField())
' AddGlyph(Me, row)
AddFilters(row, fields)
End Sub
Protected Overridable Sub AddFilters(ByVal headerRow As GridViewRow, ByVal fields As DataControlField())
For i As Integer = 0 To Columns.Count - 1
If Not Columns(i).SortExpression = [String].Empty Then
AddFilter(i, headerRow.Cells(i), fields(i))
End If
Next
End Sub
Dim m_txtFilter As New Hashtable
Dim m_ddlFilter As New Hashtable
Protected Overridable Sub AddFilter(ByVal columnIndex As Integer, ByVal headerCell As TableCell, ByVal field As DataControlField)
If headerCell.Controls.Count = 0 Then
Dim ltlHeaderText As New LiteralControl(headerCell.Text)
headerCell.Controls.Add(ltlHeaderText)
End If
Dim ltlBreak As New LiteralControl("</br>")
headerCell.Controls.Add(ltlBreak)
Dim txtFilter As TextBox = Nothing
If m_txtFilter.Contains(columnIndex) Then
txtFilter = DirectCast(m_txtFilter(columnIndex), TextBox)
Else
txtFilter = New TextBox()
txtFilter.ID = (ID & "_txtFilter") + columnIndex.ToString()
'If field.ItemStyle.Width.Value <> 0.0R Then
' txtFilter.Style.Add(HtmlTextWriterStyle.Width, Convert.ToString(field.ItemStyle.Width.Value) & "px")
'ElseIf field.HeaderStyle.Width.Value <> 0.0R Then
' txtFilter.Style.Add(HtmlTextWriterStyle.Width, Convert.ToString(field.HeaderStyle.Width.Value) & "px")
'Else
'End If
m_txtFilter(columnIndex) = txtFilter
AddHandler txtFilter.TextChanged, AddressOf Me.HandleFilterCommand
Dim js As String
js = "javascript:" & Page.GetPostBackEventReference(Me, "#####buttonPostBack") & ";"
txtFilter.Attributes.Add("onchange", js)
End If
headerCell.Controls.Add(txtFilter)
End Sub
Private Sub HandleFilterCommand(ByVal sender As Object, ByVal e As EventArgs)
'this is required to make sure that unsetting of filter is also handled
Me.RequiresDataBinding = True
' Dim filterArgs As New FilterCommandEventArgs()
'filterArgs.FilterExpression = GetFilterCommand()
Dim filterString = GetFilterCommand()
'Me.OnFilterCommand(filterArgs)
End Sub
Protected Overloads Overrides Sub OnPreRender(ByVal e As EventArgs)
Dim filterCommand As String = GetFilterCommand()
If [String].IsNullOrEmpty(filterCommand) = False Then
ApplyFilterCommand(filterCommand)
End If
MyBase.OnPreRender(e)
End Sub
Public Function IsBoundColumn(ByVal objColumn As DataControlField) As Boolean
If Not objColumn.SortExpression = String.Empty Then
Return True
End If
End Function
Protected Overridable Function GetFilterCommand() As String
' Return ""
Dim filterCommand As String = ""
Dim i As Integer = 0
While i < Me.Columns.Count
If IsBoundColumn(Me.Columns(i)) Then
If Me.HeaderRow Is Nothing Then
i = i + 1
Continue While
End If
Dim headerCell As DataControlFieldHeaderCell = DirectCast(Me.HeaderRow.Cells(i), DataControlFieldHeaderCell)
Dim txtFilter As TextBox = DirectCast(m_txtFilter(i), TextBox)
Dim aColumn As DataControlField
'If Not (TypeOf Me.Columns(i) Is BoundField) Then
' i = i + 1
' Continue While
'End If
aColumn = DirectCast(Me.Columns(i), DataControlField)
If [String].IsNullOrEmpty(txtFilter.Text) Then
i = i + 1
Continue While
End If
Dim TextValue As String = txtFilter.Text
TextValue = TextValue.Replace("'", "''")
If [String].IsNullOrEmpty(filterCommand) Then
' Convert(TimespanColumn, 'System.String'
filterCommand = "Convert(" & aColumn.SortExpression + "," + Chr(39) + "System.String" + Chr(39) + ") like " + Chr(39) + "%" + TextValue + "%" + Chr(39)
Else
filterCommand += " AND " + "Convert(" & aColumn.SortExpression + "," + Chr(39) + "System.String" + Chr(39) + ") like " + Chr(39) + "%" + TextValue + "%" + Chr(39)
End If
End If
System.Math.Max(System.Threading.Interlocked.Increment(i), i - 1)
End While
Return filterCommand
End Function
Protected Overridable Sub ApplyFilterCommand(ByVal filterCommand As String)
Dim dsv As DataSourceView = Me.GetData()
Dim objDataSourceView As ObjectDataSourceView = dsv
objDataSourceView.FilterExpression = filterCommand
Me.DataBind()
If Me.Rows.Count = 0 Then
objDataSourceView.FilterExpression = ""
Me.ShowNotFoundMessage()
Me.DataBind()
End If
End Sub
Public Sub ShowNotFoundMessage()
Dim strMessage As String = "No records found for this specified search specification."
Dim strScript As String = "alert('" & strMessage & "'); "
If (Not Me.Page.ClientScript.IsStartupScriptRegistered("clientScript")) Then
ScriptManager.RegisterClientScriptBlock(Me.Page, Me.GetType, "clientScript", strScript, True)
End If
End Sub
Public Sub SetPageSize()
'Skip hardcoded page size for role permission
If Me.PageSize <> 500 And Me.PageSize <> 25 Then
Me.PageSize = DBUtilities.GetPageSize
End If
End Sub
End Class
End Namespace
My question is, how do I access the values of the created textboxes in the calling page's code? I've tried the following but none of them work:
Label.Text = GridView1.FindControl("txtFilter3")
or
Dim row As GridViewRow = GridView1.Rows(0)
Label.Text = row.Cells(2).Text
or
Label.Text = C_C_C_CtlAccountProjectList1_GridView1_GridView1_txtFilter3