使用未解析的标识符 'timeR' -> 调用嵌套函数

Question

import UIKit

class ViewController: UIViewController {

    var timer:Timer?
    @objc func onTimerFires() {
        var timeLeft:Int = timeR()

        timeLeft -= 1
        print("\(timeLeft) seconds left")

        if timeLeft <= 0 {
            timer!.invalidate()
            timer = nil
        }
    }

    @IBAction func hardnessSelected(_ sender: UIButton) {

        timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(onTimerFires), userInfo: nil, repeats: true)

        let eggTimes:[String:Int] = [
            "Soft":5,
            "Medium":7,
            "Hard":12,
        ]

        let hardness = sender.currentTitle!

        func timeR() -> Int {
            if eggTimes[hardness]! == 5{
                return(120)
            }
            else if eggTimes[hardness]! == 7{
                return(420)
            }
            else {
                return(720)
            }
        }
        print(eggTimes[hardness]!)
    }
}

我无法提取嵌套函数，有没有办法进行内部函数调用。谢谢

Answer 1

timeR 函数被定义为 hardnessSelected 内的局部函数，因此它仅在其包含函数 hardnessSelected 内可见。

如果你想把hardness的值传递给onTimerFires，你需要把它保存到ViewController的实例属性中，这两个onTimerFires 和 hardnessSelected 可以访问。然后将timeR移动到onTimerFires，并传入hardness的值。

class ViewController: UIViewController {

    private let eggTimes:[String:Int] = [
        "Soft":5,
        "Medium":7,
        "Hard":12,
    ]

    var hardness: String?

    var timer:Timer?

    @objc func onTimerFires() {
        func timeR(hardness: String) -> Int {
            if eggTimes[hardness] == 5 {
                return 120
            } else if eggTimes[hardness] == 7{
                return 420
            } else {
                return 720
            }
        }

        var timeLeft:Int = timeR(hardness: hardness ?? "")

        timeLeft -= 1
        print("\(timeLeft) seconds left")

        if timeLeft <= 0 {
            timer!.invalidate()
            timer = nil
        }
    }

    @IBAction func hardnessSelected(_ sender: UIButton) {

        timer = Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(onTimerFires), userInfo: nil, repeats: true)

        hardness = sender.currentTitle

        print(time)
    }
}

使用未解析的标识符 'timeR' -> 调用嵌套函数

Use of unresolved identifier 'timeR' -> Calling a nested function

function-call

nested-function

swift