【发布时间】:2021-11-29 21:43:57
【问题描述】:
如何在不使用结构或类的情况下在视图控制器完成时将多个传递回多个变量? 这是我的有效代码:
class TimerViewController: UIViewController {
//DELETED UNIMPORTANT CODE
@IBAction func editTimerButtonPresed(_ sender: UIButton) {
self.performSegue(withIdentifier: "goToEditTimer", sender: self)
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToEditTimer" {
let destinationVC = segue.destination as! EditTimerViewController
destinationVC.duration = Int(myTimer.totalTime)
destinationVC.timerName = myTimer.timerName
destinationVC.completion = { [weak self] duration in
DispatchQueue.main.async {
self?.myTimer.totalTime = Double(duration!)
self?.timerLabel.text = String(duration!)
self?.timer.invalidate()
}
}
}
}
}
_
class EditTimerViewController: UIViewController, UITextFieldDelegate {
var duration: Int? //timer duration is passed from Timer
var timerName: String?
public var completion: ((Int?) -> Void)?
//DELETED UNIMPORTANT CODE
@IBAction func savePressed(_ sender: UIButton) {
timerName = timerNameField.text
let timerData = [duration!, timerName] as [Any]
completion?(timerData)
self.dismiss(animated: true, completion: nil)
}
}
但现在我想将所做的更改不仅传递给duration,还传递给timerName。
更新
按照@koen 的建议,我尝试将两个变量放在一个元组中,但我得到了一个我无法理解的错误。
在这里,我将 timerData 声明为 (Int?, String?) 的元组,但收到错误,即预期的参数类型是 Int?:
class EditTimerViewController: UIViewController, UITextFieldDelegate {
var duration: Int? //timer duration is passed from Timer
var timerName: String?
public var completion: ((Int?) -> Void)?
//DELETED UNIMPORTANT CODE
@IBAction func savePressed(_ sender: UIButton) {
timerName = timerNameField.text
var timerData = (duration: duration, name: timerName)
completion?(timerData) //ERROR Cannot convert value of type '(duration: Int?, name: String?)' to expected argument type 'Int?'
self.dismiss(animated: true, completion: nil)
}
}
但我收到以下字符串的错误:
self?.myTimer.totalTime = Double(timerData[0]!)
self?.timerLabel.text = String(timerData[1]!)
但我没有在父 VC 声明它:
class TimerViewController: UIViewController {
//DELETED UNIMPORTANT CODE
//timerData was not declared
@IBAction func editTimerButtonPresed(_ sender: UIButton) {
self.performSegue(withIdentifier: "goToEditTimer", sender: self)
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "goToEditTimer" {
let destinationVC = segue.destination as! EditTimerViewController
destinationVC.duration = Int(myTimer.totalTime)
destinationVC.timerName = myTimer.timerName
let timerData = [destinationVC.duration!, destinationVC.timerName!] as [Any]
destinationVC.completion = { [weak self] timerData in //if I check timerData it is described as Declaration let timerData: Int? Declared In TimerViewController.swift
DispatchQueue.main.async {
self?.myTimer.totalTime = Double(timerData.duration) //ERROR Argument passed to call that takes no arguments + ERROR Value of type 'Int?' has no member 'duration'
self?.timerLabel.text = String(timerData.name) //ERROR Argument passed to call that takes no arguments + ERROR Value of type 'Int?' has no member 'duration'
self?.timer.invalidate()
}
}
}
}
}
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标签: swift segue dispatch-queue