private static (IModelColumn modelColumn, IModelPositionInListViewListViewItem item) PositionMember(this ListView listView) { var item = listView.Application().Model.ModelPositionInListView() .ListViewItems.First(rule => rule.ListView.Id() == listView.Id); var modelColumn = listView.Model.Columns.FirstOrDefault(column => column.ModelMember == item.PositionMember); if (modelColumn == null) { modelColumn = listView.Model.Columns.AddNode <IModelColumn>(); modelColumn.PropertyName = item.PositionMember.Name; modelColumn.Index = -1; } return(modelColumn, item); }