Visual Basic

Public Interface IListViewFormat
    Function ListViewFormat() As String
End Interface

Public Class Aansluiting Implements IListViewFormat
    ... properties code ...

    Public Function ListViewFormat()
        return String.Format("{0} - {1}", ID, aansluiting)
    End Function

Dim collection = New List(Of IListViewFormat)
... add your items to the List and pass it to the method
Public Sub AddToListView(ByVal collection As IList(Of IListViewFormat))
    For Each item In collection
        ListView1.Items.Add(item.ListViewFormat)
    Next
End Sub

Public Class AnalogueLabel
    Inherits Label

    Property Value As Single
        Get
            Return my_Value
        End Get
        Set(value As Single)
            my_Value = value
            Me.Text = my_Value.ToString("F3")
        End Set
    End Property
    Private my_Value As Single = 0.0

End Class

<add name="ConnDB" connectionString="Data Source=localhost; Initial Catalog=DB_WB; User Id=sa; Password=123456; Integrate Security=false"
      providerName="System.Data.SqlClient"  />