Thank you for writing.
event is fired when the drag drop operation has finished. If you need the possibility to cancel the drop operation, it is necessary to use the AppointmentDropping
As to the AppointmentMoving
event, it is indeed fired when an appointment is moving. The user can control whether to allow the moving operation or not. The AppointmentMovingEventArgs.Cancel
argument allows canceling the event. I have attached a sample project for your reference.
I hope this information helps. Should you have further questions I would be glad to help.