public void SetItemsToInputList() { _inputbox.Items.Clear(); for (int i = 0; i < _BindingSourceList.Count; i++) { _BindingSourceList[i].Reeksnaam = ""; if (!(_inputlist.Contains(_BindingSourceList[i]))) { _inputlist.Add(_BindingSourceList[i]); } } foreach (extendedListbox <Ploeg> _out in _outputboxes) { _out.Items.Clear(); _out.Refresh(); } _inputbox.Refresh(); }