Не работает подписка на события

Dim txtDigit As TextBox() = New TextBox(0 To 80) {}

Private Sub txtDigit_LostFocus(ByVal sender As Object, ByVal e As EventArgs)
        Dim txt As TextBox = CType(sender, TextBox)
        txt.BorderStyle = BorderStyle.None
        Dim a As Integer = (lngNewWidth - lngWidth) / 2
        txt.Location = New Point(txt.Left + a, txt.Top + a)
        txt.Size = New Size(lngWidth, lngWidth)
    End Sub

txtDigit(Index) = New TextBox
AddHandler txtDigit(Index).LostFocus, AddressOf txtDigit_LostFocus

Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
 
        Dim txtDigit(80) As TextBox ' = New TextBox(0 To 80) {}
        Dim index As Integer
        For index = 0 To 80
            Dim txt As New TextBox
            txtDigit(index) = txt
            txt.Location = New Point(15 * index, 15)
            Me.Controls.Add(txt)
            AddHandler txtDigit(index).LostFocus, AddressOf txtDigit_LostFocus
        Next
 
 
    End Sub
 
 
    Private Sub txtDigit_LostFocus(ByVal sender As Object, ByVal e As EventArgs)
        Dim txt As TextBox = CType(sender, TextBox)
        txt.BorderStyle = BorderStyle.None
        'Dim a As Integer = (lngNewWidth - lngWidth) / 2
        'txt.Location = New Point(txt.Left + a, txt.Top + a)
        'txt.Size = New Size(lngWidth, lngWidth)
    End Sub

Private Sub txtDigit_LostFocus(ByVal sender As Object, ByVal e As EventArgs)
        Dim txt As TextBox = CType(sender, TextBox)
        txt.BorderStyle = BorderStyle.None
End Sub
Private Sub txtDigit_GotFocus(ByVal sender As Object, ByVal e As EventArgs)
        Dim txt As TextBox = CType(sender, TextBox)
        txt.BorderStyle = BorderStyle.FixedSingle
End Sub
Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim txtDigit(80) As TextBox
        Dim index As Integer
        For index = 0 To 80
            Dim txt As New TextBox
            txtDigit(index) = txt
            txt.Location = New Point(15 * index, 15)
            Me.Controls.Add(txt)
            AddHandler txtDigit(index).LostFocus, AddressOf txtDigit_LostFocus
            AddHandler txtDigit(index).GotFocus, AddressOf txtDigit_GotFocus
        Next
End Sub

AddHandler txtDigit(index).Enter, AddressOf txtDigit_Enter

Public Class BorderTextBox
    Inherits TextBox
    Protected Overrides Sub OnLostFocus(e As EventArgs)
        Me.BorderStyle = BorderStyle.None
        Me.BackColor = Color.Aqua
        MyBase.OnLostFocus(e)
    End Sub
    Protected Overrides Sub OnGotFocus(e As EventArgs)
        Me.BorderStyle = BorderStyle.None
        MyBase.OnGotFocus(e)
    End Sub
    Protected Overrides Sub OnEnter(e As EventArgs)
        Me.BorderStyle = BorderStyle.FixedSingle
        Me.BackColor = Color.Brown
        MyBase.OnEnter(e)
    End Sub
End Class