Thanks Dimitrina for your reply.
In RadGridView.Items I can find items only in actual page, not all items.
I tried to use RadGridView.SortDescriptors and CollectionViewSource to sort base collection. Unfortunately sorting by RadGridView gives me diffrent collection for this same values. For example:
Name: John, Age: 17
Name: Piter, Age: 16
Name: Rita, Age: 15
Name: Jenny, Age: 16
When I sort on "Age"
RadGridView return: Rita, Jenny, Piter, John
CollectionViewSource with RadGridView.SortDescriptors return: Rita, Piter, Jenny, John
If "RadDataPager itself does not hold a sorted collection", how RadDataPager knew which items gives to RadGridView on actual page? RadDataPager sort base collection on every time when I change page?
Thanks in advance,