Class MyToolTip
    Private ctrParent As Control
 
    Public Property ParentControl() As Control
        Get
            Return ctrParent
        End Get
        Set(ByVal value As Control)
 
            ' Neues Control?
            If Not ctrParent Is value Then
 
                ' Falls bisher Control gesetzt, Ereignisshandler entfernen
                If Not ctrParent Is Nothing Then
                    RemoveHandler ctrParent.MouseLeave, AddressOf _
                      OnParentControlMouseLeave
                End If
 
                ' neue Karte Setzen
                ctrParent = value
 
                ' Ereignishadler setzen
                AddHandler ctrParent.MouseLeave, AddressOf _
                  OnParentControlMouseLeave
            End If
        End Set
    End Property
 
    Private Sub OnParentControlMouseLeave(ByVal sender As Object, ByVal e As _
      System.EventArgs)
        ' ...
    End Sub
End Class