Share via AirDrop only - ios

Question

I want to bring out the share sheet with the AirDrop as the only option in my application.
In iOS 7, I could simple add all share types to the excludedActivityTypes property of UIActivityViewController (UIActivityTypeMessage, UIActivityTypeMail, ...)
But now in iOS 8, with the app extensions, the users may have extra sharing providers that show up.
Is there any way to show AirDrop only?
UIActivityViewController *controller = [[UIActivityViewController alloc] initWithActivityItems:#[[NSURL URLWithString:url]]
applicationActivities:nil];
NSArray *excludedActivities = #[UIActivityTypePostToTwitter, UIActivityTypePostToFacebook,
UIActivityTypePostToWeibo,
UIActivityTypeMessage, UIActivityTypeMail,
UIActivityTypePrint, UIActivityTypeCopyToPasteboard,
UIActivityTypeAssignToContact, UIActivityTypeSaveToCameraRoll,
UIActivityTypeAddToReadingList, UIActivityTypePostToFlickr,
UIActivityTypePostToVimeo, UIActivityTypePostToTencentWeibo];

Answer 1

class AirDropOnlyActivityItemSource : NSObject, UIActivityItemSource {
/// The item you want to send via AirDrop.
let item: AnyObject
init(item: AnyObject) {
self.item = item
}
func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject {
/// Use an empty URL as placeholder to let iOS Share Sheet show the AirDrop only.
return NSURL(string: "")!
}
func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? {
return item
}
}

Answer 2

Swift 4.2 version of Jonny's answer:
class AirDropOnlyActivityItemSource: NSObject, UIActivityItemSource {
///The item you want to send via AirDrop.
let item: Any
init(item: Any) {
self.item = item
}
func activityViewControllerPlaceholderItem(_ activityViewController: UIActivityViewController) -> Any {
//using NSURL here, since URL with an empty string would crash
return NSURL(string: "")!
}
func activityViewController(_ activityViewController: UIActivityViewController, itemForActivityType activityType: UIActivity.ActivityType?) -> Any? {
return item
}
}
Usage:
let itemSource = AirDropOnlyActivityItemSource(item: "test")
let activityVc = UIActivityViewController(activityItems: [itemSource], applicationActivities: nil)

Answer 3

That's currently not possible. You should file an enhancement request with apple explaining why this would be useful to the user/developer.