Limit what opens appear while sharing contact

Question

I want to share a contact inside of my application but I only want to let the user do it via Message and Mail. Can I block out all other options on the alert sheet?

func shareContacts(contacts: [CNContact]) throws {

        guard let directoryURL = FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask).first else {
            return
        }

        var filename = NSUUID().uuidString

        // Create a human friendly file name if sharing a single contact.
        if let contact = contacts.first, contacts.count == 1 {

            if let fullname = CNContactFormatter().string(from: contact) {
                filename = fullname.components(separatedBy:" ").joined(separator: "")
            }
        }

        let fileURL = directoryURL
            .appendingPathComponent(filename)
            .appendingPathExtension("vcf")

        let data = try CNContactVCardSerialization.data(with: contacts)

        try data.write(to:fileURL, options: [.atomicWrite])
         let textToShare = "This is my clear captions text test"
         let objectsToShare = [textToShare, fileURL] as [Any]
                let activityViewController = UIActivityViewController(
                    activityItems: objectsToShare,
                    applicationActivities: nil
                )

        present(activityViewController, animated: true, completion: {})
    }

Answer 1

It is not possible to simply exclude everything besides Mail and iMessage but you can do the following.

You can use a function to exclude options for the UIActivityViewController but there are only some apps you can disable. To disable more you would need a private API and you would violate the App Guidelines Apple has for all iOS Apps.

You are allowed to disable these types:

UIActivityTypePostToFacebook, 
UIActivityTypePostToTwitter, 
UIActivityTypePostToWeibo, 
UIActivityTypeMessage, 
UIActivityTypeMail, 
UIActivityTypePrint, 
UIActivityTypeCopyToPasteboard, 
UIActivityTypeAssignToContact,
UIActivityTypeSaveToCameraRoll,
UIActivityTypeAddToReadingList,
UIActivityTypePostToFlickr,
UIActivityTypePostToVimeo,
UIActivityTypePostToTencentWeibo,
UIActivityTypeAirDrop

by using this code (Xcode suggests you the exact types):

activityController.excludedActivityTypes = [
    UIActivityType.assignToContact,

    // ... and all of the types you want to disable

    // If you know the rawValue/BundleID of other types you can try to disable them too like this
    UIActivityType(rawValue: "..."),
]

Apple Documentation about UIActivityViewController

Check out this question: How to exclude Notes and Reminders apps from the UIActivityViewController?