Dim itemlist As New List(Of String)
 
 
    Private Sub frmChecked_Load(sender As Object, 
        e As EventArgs) Handles MyBase.Load
 
        'Beispiel-Liste
        For i As Integer = 0 To 20
            itemlist.Add("Item " & i.ToString)
        Next i
 
        clbo.DataSource = itemlist
    End Sub
 
 
    Private Sub SetCheckedItemsToText()
        'Checked-Items in Textbox übertragen
        tbo.Clear()
        For Each item As String In clbo.CheckedItems
            tbo.AppendText(item)
            tbo.AppendText(vbNewLine)
        Next item
    End Sub