检查用户是否在CNContactStore中有电话号码，并在此错误弹出率

Question

我正在编写一个程序，允许用户使用CNContactPickerViewController选择联系人。如果所选的联系人 NOT具有关联的电话号码，则我想将其弹出错误，并在他们命中时返回ContactPickerViewController。我已经通过断点完成了代码，并正确执行，但是它没有显示弹出的错误。

我一生都不能弄清楚为什么...这是我的代码：

 func contactPicker(_ picker: CNContactPickerViewController, didSelect contact: CNContact) {
    if contact.phoneNumbers.first?.value.stringValue != nil{
        //@TODO: check for repeats in people array
        // do something with contact
        let newPerson = Person(firstName: contact.givenName,
                               lastName: contact.familyName,
                               profileImage: #imageLiteral(resourceName: "capitalizing_on_the_economic_potential_of_foreign_entrepreneurs_feature.png") )
        if contact.imageDataAvailable == true{
            newPerson.profileImage = UIImage(data: contact.imageData!)!
        }
        // this is for the full name
        let fullname = "(contact.givenName) (contact.familyName)"
        print("The selected name is: (fullname)")
        let phoneNum = contact.phoneNumbers.first?.value.stringValue
        print("The selected phone num is: (phoneNum!)")
        //appends data to new activity model for prep to send back to home vc
        newActivity.people.append(newPerson)
        print("the people in the new activity array are: (newActivity.people)")
        peopleCollection.reloadData()
    } else {
        print("error has no number")
        let alertController = UIAlertController(title: "Error: Person has no number!", message: "", preferredStyle: .alert)
        let confirmAction = UIAlertAction(title: "Ok", style: .default, handler: {
            alert -> Void in
        })
        //add actions to alert sheet
        alertController.addAction(confirmAction)
        self.present(alertController, animated: true, completion: nil)
        //the code executes here correctly, but it does not present the alertController
    }
    //this is for phone number without dashes
    //print("the selected phone number is: ((contact.phoneNumbers[0].value ).value(forKey: "digits") as! String)")
}

Answer 1

为什么不限制用户只选择电话号码？您甚至可以隐藏所有其他字段，因此他们要么会看到电话号码，要么在没有一个接触的情况下没有任何字段（这会导致他们转到其他联系人...）在此处检查答案，它还提到过滤到电话号码：在iOS 10 Beta上的联系地址簿崩溃在这种情况下，只有在选择电话号码时才调用didSelect函数。