Swift 5 Can't get variable string from a function selected from pickerview to update Label.text

Question

这是我获取用户生日并转换日期以找到他们的年龄的地方。

//Date Picker
@IBOutlet weak var userBdayLabel: UILabel!
@IBOutlet weak var userBdayPickerScroll: UIDatePicker!


var userBday = ""
//UI BirthdayScroll
@IBAction func userBdayScrollUpdated(_ sender: Any) {
    let dateFormatter = DateFormatter()
    dateFormatter.dateStyle = .medium
    dateFormatter.timeStyle = .none
    dateFormatter.dateFormat = "MM/dd/yyyy"


    let UserBirthday = dateFormatter.string(from: userBdayPickerScroll.date)
    userBdayLabel.text = dateFormatter.string(from: userBdayPickerScroll.date)
    /// DOB String Entered
    let dob : String = UserBirthday

    /// Format Date
    let myFormatte = DateFormatter()
    myFormatte.dateFormat = "MM-dd-yyyy"

    /// Convert DOB to new Date
    let finalDate : Date = myFormatte.date(from: dob)!

    /// Todays Date
    let now = Date()
    /// Calender
    let calendar = Calendar.current

    /// Get age Components
    let ageComponents = calendar.dateComponents([.year], from: finalDate, to: now)
    print("Age is \(ageComponents.year!)")
    let userAge = String(ageComponents.year!)
    print("User age = \(userAge)")
}

我似乎无法使用IBAction之外的 UserAge ：

将用户的年龄更新为 AgeLabel：

    print("Age is \(ageComponents.year!)")
    let userAge = String(ageComponents.year!)
    print("User age = \(userAge)")
}

这是我想更新的ageLabel ，以使用他们使用我的 PickerView 选择的日期来反映用户的年龄，但我无法通过使用 UserAge 获取他们的年龄来更新 label：

//Results page
//Right Side Label Outlets for Results page
@IBOutlet weak var resultsLabel: UILabel!
@IBOutlet weak var resultView: UIView!
@IBOutlet weak var ageLabel: UILabel!
@IBOutlet weak var genderLabel: UILabel!
@IBOutlet weak var bmiResultsLabel: UILabel!
@IBOutlet weak var drinkingHabits: UILabel!
@IBOutlet weak var smokingHabits: UILabel!
@IBOutlet weak var excerciseLabel: UILabel!
@IBOutlet weak var muscleStrengthLable: UILabel!
@IBOutlet weak var educationLabel: UILabel!
@IBOutlet weak var incomeBracketLabel: UILabel!
@IBOutlet weak var stressLevelsLabel: UILabel!

如果有帮助，这是我的完整代码！

import UIKit
import Firebase

class SignUpViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

    var userAge: String = ""

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view.

    }

    //Login screen information
    @IBOutlet weak var userFirstNametext: UITextField!
    @IBOutlet weak var userLastNametxt: UITextField!
    @IBOutlet weak var userEmailtext: UITextField!
    @IBOutlet weak var UserEmailText2: UITextField!
    @IBOutlet weak var userPasswordText: UITextField!
    @IBOutlet weak var userPasswordtext2: UITextField!
    @IBOutlet weak var signUpErrorLabel: UILabel!


    //submit Login Information Password, Email, First and Last name
    @IBAction func createYourAccountButtonPressed(_ sender: Any) {

        //delete after testing everything
        self.performSegue(withIdentifier: "toVidaClockDescription", sender: nil)

        //user name, password and email text field
        let userFirstName = userFirstNametext.text
        let userLastName = userLastNametxt.text
        let userEmail = userEmailtext.text
        let userPassword = userPasswordText.text


        //Conditions for password *NEEDS WORK DATABASE
        if userFirstName != nil && userLastName != nil && userEmail != nil && userPassword == userPasswordtext2.text && userPasswordtext2.text != nil {
            print("User first name = \(String(describing: userFirstName))")
            print("User last name = \(String(describing: userLastName))")
            print("User email = \(String(describing: userEmail))")
            print("User password = \(String(describing: userPassword))")

            if userEmail!.contains("@") {
                Auth.auth().createUser(withEmail: userEmail!, password: userPassword!) { authResult, error in
                    self.performSegue(withIdentifier: "toVidaClockDescription", sender: nil)
                }
            }
        }




        //Tells everyone they are dumb for not knowing how to enter their information
        if userFirstName != nil && userLastName != nil && userEmail != nil && userPassword != nil {
            self.signUpErrorLabel.text = "Error some of your account information is incorrect. Please fix your information to continue."
            print(userFirstName!)
            print(userLastName!)
            print(userEmail!)
            print(userPassword!)
            print(userPasswordtext2.text!)
        }
    }

    //Height, Country and Weight Labels and Pickers
    @IBOutlet weak var weightCalLabel: UILabel!
    @IBOutlet weak var heightbmiLabel: UILabel!
    @IBOutlet weak var heightLabel: UILabel!
    @IBOutlet weak var heightScrollMenu: UIPickerView!
    @IBOutlet weak var weightLabel: UILabel!
    @IBOutlet weak var weightScrollMenu: UIPickerView!
    @IBOutlet weak var bmiLabel: UILabel!
    let heightToInches = (12...90).map { String($0) }
    let weightOptions  =  (50...600).map  { String($0) }
    var userWeight = 0
    var userHeight = 0

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        if pickerView.tag == 31 {
            return weightOptions.count

        }
        else{
            return heightToInches.count
        }
    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        if pickerView.tag == 30 {
            return "\(heightToInches[row])" + " Inches"
        }

        else {
            return "\(weightOptions[row])" + " Lbs"
        }
    }

    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

        if pickerView.tag == 30 {
            heightLabel.text = String(heightToInches[row]) + " Inches"
            heightbmiLabel.text = "(Height " + String(heightToInches[row]) + " Inches)²"
            userHeight = Int(Double(heightToInches[row])!)

        }

        if pickerView.tag == 31 {
            weightLabel.text =  String(weightOptions[row]) + " lbs"
            weightCalLabel.text = "Weight " + String(weightOptions[row]) + " lbs"
            userWeight = Int(Double(weightOptions[row])!)
        }

        if userHeight != 0 && userWeight != 0 {
            let userBMI = 703 * userWeight / (userHeight * userHeight)
            print(userBMI)
            if userHeight != 0 && userWeight != 0 {
                let userBMI = 703 * userWeight / (userHeight * userHeight)
                self.bmiLabel.text = ("= BMI \(userBMI) ")
                if userBMI < 18 {
                    self.bmiLabel.textColor = UIColor.red
                    self.bmiLabel.text = ("= BMI \(userBMI) ")
                }

                if userBMI > 18 && userBMI < 25 {
                    self.bmiLabel.textColor = UIColor.green
                    self.bmiLabel.text = ("BMI =\(userBMI) ")
                }

                if userBMI >= 25 && userBMI < 30 {
                    self.bmiLabel.textColor = UIColor.brown
                    self.bmiLabel.text = ("= BMI \(userBMI) ")
                }

                if userBMI > 30 {
                    self.bmiLabel.textColor = UIColor.red
                    self.bmiLabel.text = ("= BMI \(userBMI) ")
                }
            }
        }
    }


    //Date Picker
    @IBOutlet weak var userBdayLabel: UILabel!
    @IBOutlet weak var userBdayPickerScroll: UIDatePicker!


    var userBday = ""
    //UI BirthdayScroll
    @IBAction func userBdayScrollUpdated(_ sender: Any) {
        let dateFormatter = DateFormatter()
        dateFormatter.dateStyle = .medium
        dateFormatter.timeStyle = .none
        dateFormatter.dateFormat = "MM/dd/yyyy"


        let UserBirthday = dateFormatter.string(from: userBdayPickerScroll.date)
        userBdayLabel.text = dateFormatter.string(from: userBdayPickerScroll.date)
        /// DOB String Entered
        let dob : String = UserBirthday

        /// Format Date
        let myFormatte = DateFormatter()
        myFormatte.dateFormat = "MM-dd-yyyy"

        /// Convert DOB to new Date
        let finalDate : Date = myFormatte.date(from: dob)!

        /// Todays Date
        let now = Date()
        /// Calender
        let calendar = Calendar.current

        /// Get age Components
        let ageComponents = calendar.dateComponents([.year], from: finalDate, to: now)
        print("Age is \(ageComponents.year!)")
        let userAge = String(ageComponents.year!)
        print("User age = \(userAge)")
    }

    //Survey Question Number
    var questionNumber : Int = 0
    let allQuestions = SurveyQuestionBank()
    var buttonVisibility : Bool = false


    //Survey Questions UILaabels and UIButtons
    @IBOutlet weak var surveyQuestionLabel: UILabel!
    @IBOutlet weak var option1: UIButton!
    @IBOutlet weak var option2: UIButton!
    @IBOutlet weak var option3: UIButton!
    @IBOutlet weak var option4: UIButton!
    @IBOutlet weak var choiceDescriptionLabel: UILabel!


    func updateUI() {
        option1.setTitle(allQuestions.list[questionNumber].option1Text, for: .normal)
        option2.setTitle(allQuestions.list[questionNumber].option2Text, for: .normal)
        option3.setTitle(allQuestions.list[questionNumber].option3Text, for: .normal)
        option4.setTitle(allQuestions.list[questionNumber].option4Text, for: .normal)

    }

    //Survey Questions buttons
    @IBAction func surveyButtonPressed(_ sender: AnyObject) {

        if sender.tag == 1 {

            option1.isSelected = true
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            choiceDescriptionLabel!.text = allQuestions.list[questionNumber - 1].option1Explanation
            print("Button 1 Pressed")
        }

        if sender.tag == 2 {
            option1.isSelected = false
            option2.isSelected = true
            option3.isSelected = false
            option4.isSelected = false
            option1.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            choiceDescriptionLabel!.text = allQuestions.list[questionNumber - 1].option2Explanation
            print("Button 2 Pressed")
        }

        if sender.tag == 3{
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = true
            option4.isSelected = false
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            choiceDescriptionLabel!.text = allQuestions.list[questionNumber - 1].option3Explanation
            print("Button 3 Pressed")
        }

        if sender.tag == 4 {
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = true
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            choiceDescriptionLabel!.text = allQuestions.list[questionNumber - 1].option4Explanation
            print("Button 4 Pressed")
        }
        if sender.tag == 10 && questionNumber == 9 {
            performSegue(withIdentifier: "surveyResultsSegue", sender: nil)
        }

        //reset view to not show segue
        if sender.tag == 10 && questionNumber == 0 {
            performSegue(withIdentifier: "surveyResultsSegue", sender: nil)
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = 1
        }

            //if options aren't selected then nothing happens in survey question
        else if sender.tag == 10 && option1.isSelected == false && option2.isSelected == false && option3.isSelected == false && option4.isSelected == false {
            print("1a")
            choiceDescriptionLabel.text = "Whoops! You haven't selected an answer! Please select an answer to continue."
        }

            //checks to see if option 1 is selcted in view
        else if sender.tag == 10 && option1.isSelected == true && option2.isSelected == false && option3.isSelected == false {
            print("1a")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }

        else if sender.tag == 10 && option1.isSelected == true && option2.isSelected == false && option3.isSelected == false && option4.isSelected == false {
            print("1b")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }

            //checks to see if 2 is selected
        else if sender.tag == 10 && option1.isSelected == false && option2.isSelected == true && option3.isSelected == false {
            print("2a")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }

        else if sender.tag == 10 && option1.isSelected == false && option2.isSelected == true && option3.isSelected == false && option4.isSelected == false {
            print("2b")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }

            //checks to see if 3 is selected
        else if sender.tag == 10 && option1.isSelected == false && option2.isSelected == false && option3.isSelected == true {
            print("3a")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }

        else if sender.tag == 10 && option1.isSelected == false && option2.isSelected == false && option3.isSelected == true && option4.isSelected == false {
            print("3b")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }


            //checks to see if option 4 is selected
        else if sender.tag == 10 && option1.isSelected == false && option2.isSelected == false && option3.isSelected == false && option4.isSelected == true {
            print("4a")
            option1.backgroundColor = UIColor.lightGray
            option2.backgroundColor = UIColor.lightGray
            option3.backgroundColor = UIColor.lightGray
            option4.backgroundColor = UIColor.lightGray
            nextQuestion()
            checkAnswerVisibility()
            updateUI()
            choiceDescriptionLabel.text = ""
            questionNumber = questionNumber + 1
            option1.isSelected = false
            option2.isSelected = false
            option3.isSelected = false
            option4.isSelected = false
        }

        option1.setTitleColor(.white, for: .selected)
        option2.setTitleColor(.white, for: .selected)
        option3.setTitleColor(.white, for: .selected)
        option4.setTitleColor(.white, for: .selected)
        print(questionNumber)


    }


    func updateAnswerDescription() {
        //Gets survey choice description
        surveyQuestionLabel!.text = allQuestions.list[questionNumber].questionText
    }


    //THis just checks if Option Button are visiable or not.
    func checkAnswerVisibility() {

        //Gets the options text from the Survey Question Bank from swift
        let option1Visibility = allQuestions.list[questionNumber].answer1Visibility
        let option2Visibility = allQuestions.list[questionNumber].answer2Visibility
        let option3Visibility = allQuestions.list[questionNumber].answer3Visibility
        let option4Visibility = allQuestions.list[questionNumber].answer4Visibility

        option1.isHidden = option1Visibility
        option2.isHidden = option2Visibility
        option3.isHidden = option3Visibility
        option4.isHidden = option4Visibility

    }

    //UPDATE TEXTs from question bank
    func nextQuestion() {
        surveyQuestionLabel.font = UIFont.preferredFont(forTextStyle: .body)
        surveyQuestionLabel.adjustsFontForContentSizeCategory = true
        surveyQuestionLabel!.text = allQuestions.list[questionNumber].questionText
        option1.titleLabel!.text = allQuestions.list[questionNumber].option1Text
        option2.titleLabel!.text = allQuestions.list[questionNumber].option2Text
        option3.titleLabel!.text = allQuestions.list[questionNumber].option3Text
        option4.titleLabel!.text = allQuestions.list[questionNumber].option4Text

    }
    /*
     // MARK: - Navigation

     // In a storyboard-based application, you will often want to do a little preparation before navigation
     override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
     // Get the new view controller using segue.destination.
     // Pass the selected object to the new view controller.
     }
     */
    func startOver() {
        print("right before startover")
        questionNumber = 0
        updateUI()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    class CustomButton: UIButton {

        override var isHighlighted: Bool {
            didSet {
                if (isHighlighted) {
                    super.isHighlighted = false
                    titleLabel?.textColor = .white
                }
            }
        }
    }

    //Results page
    //Right Side Label Outlets for Results page
    @IBOutlet weak var resultsLabel: UILabel!
    @IBOutlet weak var resultView: UIView!
    @IBOutlet weak var ageLabel: UILabel!
    @IBOutlet weak var genderLabel: UILabel!
    @IBOutlet weak var bmiResultsLabel: UILabel!
    @IBOutlet weak var drinkingHabits: UILabel!
    @IBOutlet weak var smokingHabits: UILabel!
    @IBOutlet weak var excerciseLabel: UILabel!
    @IBOutlet weak var muscleStrengthLable: UILabel!
    @IBOutlet weak var educationLabel: UILabel!
    @IBOutlet weak var incomeBracketLabel: UILabel!
    @IBOutlet weak var stressLevelsLabel: UILabel!
}

Answer 1

您已经创建了 userAge 变量，只需将您的值存储在该变量中

class SignUpViewController: UIViewController, UIPickerViewDelegate, 
UIPickerViewDataSource{

var userAge: String = ""

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view.

} 

像下面这样使用这个变量，并给它赋值。 现在您可以在 Button 操作方法之外使用它的值

print("Age is \(ageComponents.year!)")
userAge = String(ageComponents.year!)
print("User age = \(userAge)")

Answer 2

我通过为每个单独的视图制作单独的视图控制器解决了这个问题

然后通过提供委托来传递每个变量。