ItemUpdating and ItemAttachmentAdded

When I attach a file to the SPListItem, it always run the ItemUpdating method first.And In the ItemUpdating method,I update the SPListItem

properties.Status = SPEventReceiverStatus.CancelNoError;

Then the ItemAttachmentAdded method doesn't worked.

I just want to run the ItemAttachmentAdded method.(File has been updated)

How to run ItemAttachmentAdded method first

Or how to know I have attached a file in the ItemUpdating method