Today, the SfPicker triggers an event when the selection is changed using the
SelectionChanged event. However, this only gets triggered when the user selects a new value and then releases the screen. As long as the user selects values and keeps his/her finger on the screen, no event is triggered.
The new event would detect any change in value while the user is holding the screen (SelectionChanging).
Use case: on iOS, when selecting the hour of an event in the calendar app and that hour goes from 11 to 12 while holding, AM jumps automatically to PM in the last column. Today, this is not possible using the current event as the user needs to let go of the screen before triggering the SelectionChanged event.