There is the possibility to sort at the point where you define your Collection View. This is especially useful for sorting Selective List items! An example is as follows:
<source lang = "xml">
xmlns:cv="using:UBIK.WinX.UI.CollectionView"
<cv:ListCollectionView x:Key="SortedList" ItemsSource="{Binding EditDialogViewModel.PropertyItem, Converter={StaticResource SelectiveListToItemsConverter}}">
<cv:ListCollectionView.SortDescriptions>