ios - 在具有委托(delegate)的 View Controller 之间传递多个值

Question

我已经成功地在具有委托(delegate)函数的 View Controller 之间传递了一段数据(一个 String 变量、一个 Int 变量等)。但是，我还没有设法通过委托(delegate)函数传递各种数据。

我收到以下错误:

*** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<UIViewController 0x7faea770db60> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key receivingAmountLabel.'

如果我删除 receingAmountLabel，错误将转到另一个 UI 元素。如果我删除该元素，它会继续到另一个。

所有 UI 元素都按应有的方式连接。相关代码如下所示:

FirstVC.swiftFirstVC 类:UIViewController、DataSentDelegateMax {

@IBOutlet weak var receivingStringLabel: UILabel!
@IBOutlet weak var receivingAmountLabel: UILabel!

func userDidEnterData(stringData: String, amountData: Int) {
    receivingStringLabel.text = stringData
    receivingAmountLabel.text = String(amountData)
}


override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
    if (segue.identifier == "showSecondVC") {
        let secondVC = segue.destination as! SecondVC
        secondVC.delegate = self
    }
}

SecondVC.swift

protocol DataSentDelegateMax {
    func userDidEnterData(stringData: String, amountData: Int)
}

    @IBOutlet weak var stringTF: UITextField!
    @IBOutlet weak var amountTF: UITextField!

    var delegate: DataSentDelegateMax? = nil

    @IBAction func sendButtonAction(_ sender: Any) {
        if delegate != nil {
            if (stringTF.text != nil) {
                if (Int(amountTF.text!) != nil) {
                    let stringData = stringTF.text
                    let amountData = Int(amountTF.text!)
                    delegate?.userDidEnterData(stringData: stringData!, amountData: amountData!)
                    dismiss(animated: true, completion: nil)
                }
            }
        }
    }

尝试在委托(delegate)中传递字典时，我遇到了同样的问题。

Answer 1

使用下面的简化代码:

   if let del = delegate, let stringData = stringTF.text, let amountData = amountTF.text  {
        del.userDidEnterData(stringData: stringData, amountData: amountData)
        dismiss(animated: true, completion: nil)
    }