无法从UITextField退出FirstResponder

Question

Do you know(can you see) why I can not resign from FirstResponder and hide the keyboard?

FYI: Xcode 9

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet weak var label: UILabel!
    @IBOutlet weak var text: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()

        self.text.delegate = self
        let tap = UITapGestureRecognizer(target: self, action: #selector(ViewController.tapFunction))
        label.isUserInteractionEnabled = true
        label.addGestureRecognizer(tap)
    }

    var keyboardInputEnabled = true
    @objc func tapFunction(sender:UITapGestureRecognizer) {
        if self.keyboardInputEnabled {
            self.text.becomeFirstResponder()
        }else{
            self.view.endEditing(true)
            self.text.resignFirstResponder()
        }
        self.keyboardInputEnabled = !self.keyboardInputEnabled
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        return self.keyboardInputEnabled
    }

    func textFieldShouldEndEditing(_ textField: UITextField) -> Bool {
        return self.keyboardInputEnabled
    }

    func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
        return self.keyboardInputEnabled
    }


    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

}

Answer 1

Because textFieldShouldEndEditing return false the second time you run tapFunction which prevent it to end editing mode.

Taken from this

Normally, you would return true from this method to allow the text field to resign the first responder status. You might return false, however, in cases where your delegate detects invalid contents in the text field. Returning false prevents the user from switching to another control until the text field contains a valid value.

Answer 2

Try

self.view.endEditing(true) for disabling keyboard