Fires after the selected date has been changed within the calendar.
The SelectionChanged event's data class is EventArgs.
Write a handler for the SelectionChanged event to perform server-side tasks in response to an end-user clicking the date selector controls within the calendar.
The SelectionChanged event's generation depends upon the settings of the ASPxEdit.AutoPostBack property and the ASPxClientProcessingModeEventArgs.processOnServer property passed to the corresponding client ASPxClientCalendar.SelectionChanged event, if it is handled. refer to the descriptions of these properties for more information.