CNContactPickerViewController [CNUI 错误] 错误调用服务 - 无法与帮助程序应用程序

Question

我使用以下代码让用户从保存的联系人中选择联系人：

import UIKit
import ContactsUI
class AddGroupViewController:UIViewController{

  var contacts:[Contact] = []
  var selectecPhoneBookContacts:[String] = []
  override func viewDidLoad() {
  }
  @IBAction func selectPhoneBook(_ sender: Any) {
    let contactPicker = CNContactPickerViewController()
    contactPicker.displayedPropertyKeys = [
      CNContactGivenNameKey, CNContactFamilyNameKey
    ]
    contactPicker.delegate = self
    if !selectecPhoneBookContacts.isEmpty{
      contactPicker.predicateForEnablingContact = CNContact.predicateForContacts(withIdentifiers: selectecPhoneBookContacts)
    }
    self.present(contactPicker, animated: true, completion: nil)
  }
}
extension AddGroupViewController:CNContactPickerDelegate{
  func contactPicker(_ picker: CNContactPickerViewController, didSelect contacts: [CNContact]) {
    for contact in contacts{
      selectecPhoneBookContacts.append(contact.identifier)
    }
  }
}

第一次它完美运行。但是第二次，当执行此代码时

if !selectecPhoneBookContacts.isEmpty{
      contactPicker.predicateForEnablingContact = CNContact.predicateForContacts(withIdentifiers: selectecPhoneBookContacts)
    }

我最终遇到了错误：

2017-02-03 09:23:37.501 SmartList[57062:10996092] viewServiceDidTerminateWithError:: Error Domain=_UIViewServiceInterfaceErrorDomain Code=3 "(null)" UserInfo={Message=Service Connection Interrupted}
2017-02-03 09:23:37.504 SmartList[57062:10996203] [CNUI ERROR] error calling service - Couldn’t communicate with a helper application.
2017-02-03 09:23:47.479 SmartList[57062:10996092] [CNUI ERROR] Contact picker delayed appearance timed out - YES
2017-02-03 09:23:57.480 SmartList[57062:10996092] [CNUI ERROR] Contact picker delayed appearance timed out - YES

我想做的是：让用户只选择联系人一次。如果联系人被选中一次，则无法再次添加

Answer 1

我通过使用自己的NSPredicate解决了这个问题：

if !selectecPhoneBookContacts.isEmpty{
  contactPicker.predicateForEnablingContact = NSPredicate(format: "NOT(identifier IN %@)", selectecPhoneBookContacts)
}