Public Class frmCheckIt
 
    Dim cbos As New List(Of CheckBox)
    Dim cbo_count As Integer = 60
 
    Dim cbo_height As Integer = 20
    Dim btn_height As Integer = 25
 
    'Button für Invertierung aller Checkboxen 
    Dim WithEvents btnCheck As New Button With _
        {.Parent = Me, .Width = 150, .Height = 25, .Text = "Check"}
 
    Dim checkchanged_handled As Boolean = False
 
    'Panel, Container der Checkboxen
    Dim plCheck As New Panel With _
                 {.Parent = Me, .Top = btn_height + 5, _
                  .Width = 180, .Height = 20 * cbo_height + 20, _
                  .AutoScroll = True, .BorderStyle = BorderStyle.Fixed3D}
 
    'Tooltips für Checkboxen
    Dim ttcheck As New ToolTip
 
 
    Private Sub frmCheckIt_Load(sender As System.Object, _
                                e As System.EventArgs) Handles MyBase.Load
 
        Me.Height = btnCheck.Height + plCheck.Height + 50
 
        For i As Integer = 1 To cbo_count
            'Checkbox erstellen und einrichten
            Dim cbo As New CheckBox With { _
                .Parent = plCheck, _
                .Tag = i, _
                .Text = "Check " & CStr(i), _
                .Top = (i - 1) * cbo_height, _
                .Width = 150}
            'Checkbox-Referenz listen 
            cbos.Add(cbo)
            'Ereignisverarbeitung der Checkbox einrichten
            AddHandler cbo.CheckedChanged, AddressOf cbo_checkedchanged
            'Tooltip erstellen
            ttcheck.SetToolTip _
            (cbo, "Ich bin eine Checkbox. Mein Listen-Index ist " & CStr(i - 1))
        Next i
    End Sub
 
 
    Private Sub cbo_checkedchanged(sender As Object, e As EventArgs)
        Dim cbo As CheckBox = DirectCast(sender, CheckBox)
        If Not checkchanged_handled Then
            MsgBox("Checkbox" & cbo.Text & " wurde geändert")
        End If
    End Sub
 
 
    Private Sub btnCheck_Click(sender As Object, _
                               e As System.EventArgs) Handles btnCheck.Click
 
        checkchanged_handled = True
        For i As Integer = 0 To cbos.Count - 1
            'indizierter Zugriff
            cbos(i).Checked = Not cbos(i).Checked
        Next i
        checkchanged_handled = False
    End Sub
End Class