How to disable Drag/Drop

You have to handle BeforeEditAction for an event. Take a look at sample method: CCalendarDemoView::OnEvent_BeforeEditAction

Below is sample piece of code which does what you need:

void CCalendarDemoView::OnEvent_BeforeEditAction(XTP_NOTIFY_CODE Event,
WPARAM wParam, LPARAM lParam)
{ 
if (XTP_NC_CALENDAR_BEFORE_EVENT_EDIT_OPERATION != Event) {
ASSERT(FALSE);
return;
}
  
XTP_EVENT_EDIT_OPERATION_PARAMS* pOPparams = (XTP_EVENT_EDIT_OPERATION_PARAMS*)wParam;
BOOL* pbHandled = (BOOL*)lParam;
ASSERT(pbHandled && pOPparams);

// check is already canceled/handled
if(!pOPparams || !pbHandled || *pbHandled) {
return;
}

if(pOPparams->eOperation == xtpCalendarEO_DragCopy ||
pOPparams->eOperation == xtpCalendarEO_DragMove)
{
XTP_EVENT_DRAG_OPERATION_PARAMS* pParamsDrag = (XTP_EVENT_DRAG_OPERATION_PARAMS*)wParam;
if (pParamsDrag->pDraggingEvent->GetScheduleID() !=
pParamsDrag->pDraggingEventNew->GetScheduleID())
{
*pbHandled = TRUE;
return;
}
}
....
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