Selects the previous appointment within the visible area of the view.
The SelectPrevAppointment method allows the appointment before the currently selected one to be selected. If no appointment is currently selected, the previous appointment whose start time is less than the start time of the selected time interval is selected.
To select the next appointment, use the SchedulerControl.SelectNextAppointment method.
End-users can use the TAB and TAB+SHIFT keys to select the next and previous appointments, respectively.
Each time the selection changes, the SchedulerControl.SelectionChanged event is raised.
The SelectPrevAppointment method is analogous to the TAB key switching in that it selecs appointments within the visible range only.