NSAttributedStringKey giving an unresolved identifier error

Question

I\'m following an online tutorial to build a magazine type iOS application. I\'m attempting to use NSAttributedStringKey but keep getting the error shown below. Any ideas?

Answer 1

This example works only iOS11.

import UIKit

class VC: UIViewController { 

    @IBOutlet weak var usernameTxt: UITextField!
    @IBOutlet weak var emailTxt: UITextField!
    @IBOutlet weak var passTxt: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        setupView()
    }

    func setupView() {
        usernameTxt.attributedPlaceholder = NSAttributedString(string: "username", attributes: [NSAttributedStringKey.foregroundColor: smackPurplePlaceholder])
        emailTxt.attributedPlaceholder = NSAttributedString(string: "email", attributes: [NSAttributedStringKey.foregroundColor: smackPurplePlaceholder])
        passTxt.attributedPlaceholder = NSAttributedString(string: "password", attributes: [NSAttributedStringKey.foregroundColor: smackPurplePlaceholder])  
    }    
}