在 Swift 中设置日期选择器和文本字段时激活按钮

Question

我想实现一个在设置文本字段和日期选择器时激活按钮的功能。

日期选择器的值转到标签，我通过更改标签值检查了按钮。

但是，在我实现的其他功能中，如果使用单例对象弹出导航并在返回时保存值，如果通过标签更改检查按钮，则不会激活按钮，因为它是与单例重复，或者即使只设置了电话号码。碰巧按钮被激活了。

那么，除了更改标签之外，有没有办法在日期选择器本身更改值时捕获它？

import UIKit

class ThirdViewController: UIViewController {
    
    lazy var dateFormatter: DateFormatter = {
        let date = DateFormatter()
        date.dateStyle = .medium
        date.timeStyle = .none
        return date
    }()
    
    @IBOutlet weak var dateLabel: UILabel!
    @IBOutlet weak var numberTextField: UITextField!
    @IBOutlet weak var datePicker: UIDatePicker!
    @IBOutlet weak var signUpButton: UIButton!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        numberTextField.addTarget(self, action: #selector(editingChanged(_:)), for: .editingChanged)
        numberTextField.text = UserInformation.userInformationSingleton.userNumber
        dateLabel.text = UserInformation.userInformationSingleton.dateLabel
    }
    
    @objc func editingChanged(_ textField: UITextField) {
        if textField.text?.count == 1 {
            if textField.text?.first == " " {
                textField.text = ""
                return
            }
        }
        toggleButton()
    }
    
    func toggleButton() {
        guard
            let textField = numberTextField.text, !textField.isEmpty,
            dateLabel.text != ""
            else {
                signUpButton.isEnabled = false
                return
        }
        signUpButton.isEnabled = true
    }
    
    @IBAction func datePickerValueChanged(_ sender: UIDatePicker) {
        dateLabel.text = dateFormatter.string(from: sender.date)
        toggleButton()
    }
    
    @IBAction func cancelButton(_ sender: UIButton) {
        self.dismiss(animated: true, completion: nil)
        UserInformation.userInformationSingleton.userID = nil
        UserInformation.userInformationSingleton.userNumber = nil
        UserInformation.userInformationSingleton.dateLabel = nil
    }
    
    @IBAction func tappedPreviousButton(_ sender: UIButton) {
        self.navigationController?.popViewController(animated: true)
    }
    
    @IBAction func tappedSignUpButton(_ sender: UIButton) {
        self.dismiss(animated: true, completion: nil)
    }
}

https://i.stack.imgur.com/a1GVc.png

感谢阅读！！

Answer 1

解决了问题！

func toggleButton() {
        guard
            let textField = numberTextField.text, !textField.isEmpty,
            let label = dateLabel.text, !label.isEmpty
            else {
                signUpButton.isEnabled = false
                return
        }
        signUpButton.isEnabled = true
    }