I want to describe about my scenario. When I click on a day, I want whole week is selected instead of one day, so I can not use SelectionChanging event, because when user click, the SelectionChanging is raised, then I get the selected date by e.NewDates, I calculate and add dates in week from that date, then add to SelectedDates property, this will raise SelectionChaging again.
Therefore, I don't use SelectionChanging event, I use Click event and get the last clicked date from FocusedDate Property. I have just found this property, and it work find.
Thank for your answer.