How to retrieve address book contacts with Swift?

2020-02-21 17:21发布

I don't understand why my code doesn't compile with Swift.

I am trying to convert this Objective-C code:

CFErrorRef error = NULL;
ABAddressBookRef addressBook = ABAddressBookCreateWithOptions(NULL, &error);

  if (addressBook != nil) { 
    NSLog(@"Succesful."); 

    NSArray *allContacts = (__bridge_transfer NSArray *)ABAddressBookCopyArrayOfAllPeople(addressBook);
}

This is my current rendition in Swift:

var error:CFErrorRef
var addressBook = ABAddressBookCreateWithOptions(nil, nil);

if (addressBook != nil) {
    println("Succesful.");

    var allContacts:CFArrayRef = ABAddressBookCopyArrayOfAllPeople(addressBook);
}

but, Xcode reports:

'Unmanaged' is not convertible to 'CFArrayRef'

Do you guys have an idea ?

1条回答
再贱就再见
2楼-- · 2020-02-21 18:06

Obviously, if targeting iOS version 9 or greater, you shouldn't use the AddressBook framework at all, and instead use the Contacts framework instead.

So,

  1. Import Contacts:

    import Contacts
    
  2. Make sure to supply a NSContactsUsageDescription in your Info.plist.

  3. Then, you can then access contacts. E.g. in Swift 3:

    let status = CNContactStore.authorizationStatus(for: .contacts)
    if status == .denied || status == .restricted {
        presentSettingsActionSheet()
        return
    }
    
    // open it
    
    let store = CNContactStore()
    store.requestAccess(for: .contacts) { granted, error in
        guard granted else {
            DispatchQueue.main.async {
                self.presentSettingsActionSheet()
            }
            return
        }
    
        // get the contacts
    
        var contacts = [CNContact]()
        let request = CNContactFetchRequest(keysToFetch: [CNContactIdentifierKey as NSString, CNContactFormatter.descriptorForRequiredKeys(for: .fullName)])
        do {
            try store.enumerateContacts(with: request) { contact, stop in
                contacts.append(contact)
            }
        } catch {
            print(error)
        }
    
        // do something with the contacts array (e.g. print the names)
    
        let formatter = CNContactFormatter()
        formatter.style = .fullName
        for contact in contacts {
            print(formatter.string(from: contact) ?? "???")
        }
    }
    

    Where

    func presentSettingsActionSheet() {
        let alert = UIAlertController(title: "Permission to Contacts", message: "This app needs access to contacts in order to ...", preferredStyle: .actionSheet)
        alert.addAction(UIAlertAction(title: "Go to Settings", style: .default) { _ in
            let url = URL(string: UIApplicationOpenSettingsURLString)!
            UIApplication.shared.open(url)
        })
        alert.addAction(UIAlertAction(title: "Cancel", style: .cancel))
        present(alert, animated: true)
    }
    

My original answer for AddressBook framework is below.


A couple of observations:

  • If you want to use error parameter of ABAddressBookCreateWithOptions, define it to be Unmanaged<CFError>?.

  • If it fails, take a look at the error object (doing takeRetainedValue so you don't leak).

  • Make sure to takeRetainedValue of the address book, too, so you don't leak.

  • You probably shouldn't just grab the contacts, but you probably should request permission first.

Pulling that all together you get:

// make sure user hadn't previously denied access

let status = ABAddressBookGetAuthorizationStatus()
if status == .Denied || status == .Restricted {
    // user previously denied, so tell them to fix that in settings
    return
}

// open it

var error: Unmanaged<CFError>?
guard let addressBook: ABAddressBook? = ABAddressBookCreateWithOptions(nil, &error)?.takeRetainedValue() else {
    print(error?.takeRetainedValue())
    return
}

// request permission to use it

ABAddressBookRequestAccessWithCompletion(addressBook) { granted, error in
    if !granted {
        // warn the user that because they just denied permission, this functionality won't work
        // also let them know that they have to fix this in settings
        return
    }

    if let people = ABAddressBookCopyArrayOfAllPeople(addressBook)?.takeRetainedValue() as? NSArray {
        // now do something with the array of people
    }
}
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