I've created my custom Event Receiver that works well and works on ItemAdding and ItemUpdating.
But if an user try to modify a calendar event using drag 'n drop, I'm not able to intercept that update.
I explain my scenario. An user add a new event in a calendar (with new event button). When the event is created my Event Receiver check if there are already other events in the same date. If is it true, it shows an error message. In calendar view of Sharepoint, users are also able to modify events date by drag and drop. So, my Event Receiver could be able to check overlapping events also in this moment. But, ItemAdding method or ItemUpdating aren't working for me.
What kind of method should I use?