如何将文本字段中的数据推送到另一个 VC 中的标签

Question

我有带有 4 个标签和 4 个 goToVC 按钮的 mainVC，每个按钮使用 segue 来呈现另外 4 个 VC。每个 vc 都有 textField 和 doneButton。我想在 mainVC 标签中显示 textField 中的文本，并且我想使用委托。但相反，我得到了空标签。请帮忙。

委托.swift

protocol TextFieldDelegate {
    func didFinishTextField(text: String)
} 

MainVC.swift

class MainViewController: UIViewController, TextFieldDelegate {
    
    @IBOutlet weak var redText: UILabel!
    @IBOutlet weak var orangeText: UILabel!
    @IBOutlet weak var pinkText: UILabel!
    @IBOutlet weak var purpleText: UILabel!
    
    var choosenLabel: UILabel?
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        }
    
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        if segue.identifier == "toRedVC" {
            let vc = segue.destination as! RedViewController
            vc.delegate = self
            choosenLabel = redText
        } else if segue.identifier == "toOrangeVC" {
            let vc = segue.destination as! OrangeViewController
            vc.delegate = self
            choosenLabel = orangeText
        } else if segue.identifier == "toPinkVC" {
            let vc = segue.destination as! PinkViewController
            vc.delegate = self
            choosenLabel = pinkText
        } else if segue.identifier == "toPurpleVC" {
            let vc = segue.destination as! PurpleViewController
            vc.delegate = self
            choosenLabel = purpleText
        }
    }
    
    func didFinishTextField(text: String) {
        if let data = choosenLabel {
            data.text = text
        }
    }
   
    @IBAction func redButton(_ sender: UIButton) {
    }
    @IBAction func orangeButton(_ sender: UIButton) {
    }
    @IBAction func pinkButton(_ sender: UIButton) {
    }
    @IBAction func purpleButton(_ sender: UIButton) {
    }
}

RedVC(其他3个相同).swift

class RedViewController: UIViewController {

    
    var delegate: TextFieldDelegate?
    var textVar: String = ""
    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }
    
    @IBAction func textField(_ sender: UITextField) {
        if let data = sender.text {
            textVar = data
        }
    }
    @IBAction func doneButton(_ sender: UIButton) {
        delegate?.didFinishTextField(text: textVar)
        dismiss(animated: true, completion: nil)
    }
}

Answer 1

您的代码似乎一切正常。我建议您检查您的文本字段的操作是否在 ViewController 中设置为 editingChanged。