Is there a way to detect if user presses accept or deny for Airdrop request?

Question

So, I have the airdrop feature working but I need different things to happen if the user presses accept and if the user presses deny for the airdrop request.

Currently, the same actions happen whether the user accepts or denies the airdrop request.

I'm using

activityViewController.SetCompletionHandler(HandleActivityViewControllerCompletion);

which has this signature:

private async void HandleActivityViewControllerCompletion (NSString activityType, bool completed, NSExtensionItem[] returnedItems, NSError error)

The problem is none of these parameters I can use. Completed always returns true if the user makes either choice and returnedItems is null.

What can I use or do to detect if the user denied the Airdrop request?

This is for a Xamarin.iOS app but answers in Swift/native iOS are fine too.

Similar SO question with no answer: UIActivityViewController Airdrop - Check the status when 'sent' or 'declined'

Answer 1

Hm, okay, it looks like a look into the crystal ball is unavoidable to answer this.

I tried it out on iOS 10.3.3 and indeed there is no difference in behavior of this method, regardless of whether the Airdrop was accepted by the other device or declined.

Apparently, the completed boolean in the HandleActivityViewControllerCompletion so far means this: "The data was given to a selected activity" or "The data was not given to any activity". It corresponds to whether the button below the share sheet says "Done" or "Cancel". Unfortunately the airdrop activity sets this button to Done even when the drop was declined and well, that kind of makes sense, because it "did something".

I think the problem (design wise) lies in the fact that, usually, activities (custom ones, for example) dismiss the entire UIActivityViewController when they call activityDidFinish(_:). The AidropActivity is obviously special in that it doesn't seem to do that at all, it just displays a "Declined" indicator below its icon when the connection goes through but the other side, well, declines. Plus it changes the sheet's button.

Besides, the entire operation is asynchronous. To me it looks like the Airdrop activity calls its perform() or prepare(withActivityItems:) function, starts a remote connection asynchronously and immediately sets the button to "Done" while that is running (I don't even see a way for other activities to do that, but I didn't try). You can even press Done before the other side has accepted or declined, that won't abort the transfer. The Activity even gets notified (if the sheet wasn't yet closed with "Done") to update its icon.

All in all it appears to have special privileges, which makes sense, as the entire Airdrop functionality is special: It runs in the background. The activity merely passes it data and as soon as that's done, itself is done as well (regardless of outcome).

Of course I agree that this is insufficient, but I changing this would probably require Apple to change the API. So it'd be a feature request for you, I strongly doubt there's a (AppStore conform) workaround that I didn't think of...