Get decline event in VSTO

Question

We need to handle decline event for outlook add-in.
But on decline an appointment, cancel event is getting executed as appointment is moved to delete folder from the default folder.
I tried solution given in the below link
http://stackoverflow.com/questions/25619796/capturing-accept-decline-propose-new-time-event-in-outlook-add-in-c-sharp-for-me
But using this I can obtain event only for Decline – DoNotSendResponse and also it is working only if user opens the appointment and declines it from the ribbon bar.
We want to handle decline event from all the places which are
Appointment => Right click => Decline
Invitation mail => Decline
Open appointment => Ribbon => Decline
And event should be triggered for all the child scenarios which are
Decline – Edit Response before send
Decline – Send response now
Decline – Do not send response
We want to track Decline as separate event because we have different code for Cancel\Delete events.
Is there any way By which we can get to know in event 'apptItem_BeforeDelete' or 'mapi12Event2.BeforeItemMove'
whether it is declined or cancelled?
Regards
Neeraj
Neeraj

Answer 1

Hello Neeraj,
Try to handle the
PropertyChange and
CustomPropertyChange events of Outlook items. The first one is fired
when an explicit built-in property (for example, Subject)
of an instance of the parent object is changed. The
CustomPropertyChange event is fired when a custom property of an item (which is an instance of the parent object) is changed.
Also you may consider repurposing the Ribbon UI controls. See
Temporarily Repurpose Commands on the Office Fluent Ribbon for more information.