Question

我有一个UIProgress视图，它需要60秒才能在屏幕上显示，但是如何将它设置在某个位置而不是将时间设置为“ var seconds = 60”呢？（不包括所有代码。）

import UIKit

class MinuteMeditation: UIViewController {
    @IBOutlet weak var progressController: UIProgressView!
    @IBOutlet weak var statusLabel: UILabel!
    @IBOutlet weak var timeLabel: UILabel!

let savedTime = UserDefaults.standard.string(forKey: "time")

var seconds = 60 // THIS IS WHERE I WANT THE USER DEFAULTS ^
var timer = Timer()
var isTimerRunning = false
var resumeTapped = false


override func viewDidAppear(_ animated: Bool) {
    super.viewDidAppear(animated)

    runTimer()

Answer 1

一种方法是在UIViewController生命周期的某个时刻分配值，例如，如果您想每次显示视图时都使用保存的值，则可以使用viewWillLoad ，或者viewLoaded，如果您只想在系统首次加载视图时进行设置，例如...

class MinuteMeditation: UIViewController {
    @IBOutlet weak var progressController: UIProgressView!
    @IBOutlet weak var statusLabel: UILabel!
    @IBOutlet weak var timeLabel: UILabel!

    var seconds: TimeInterval = 60.0 // THIS IS WHERE I WANT THE USER DEFAULTS ^
    var timer = Timer()
    var isTimerRunning = false
    var resumeTapped = false

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        if let savedTime = UserDefaults.standard.string(forKey: "time"), let time = Double(savedTime) {
            seconds = time
        }
    }


    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        runTimer()
    }
}

请记住，这将始终覆盖先前设置的任何值。如果您希望仅在以前未设置过该值的情况下使用保存的值，则需要将seconds设为可选，并在以前未设置且没有保存的值的情况下分配默认值< / p>

另一种选择是使seconds为计算值...

class MinuteMeditation: UIViewController {
    @IBOutlet weak var progressController: UIProgressView!
    @IBOutlet weak var statusLabel: UILabel!
    @IBOutlet weak var timeLabel: UILabel!

    var seconds: TimeInterval {
        guard let savedTime = UserDefaults.standard.string(forKey: "time"), let time = Double(savedTime) else {
            return 60.0
        }
        return time
    }
    var timer = Timer()
    var isTimerRunning = false
    var resumeTapped = false

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)

        runTimer()
    }
}

这确实意味着该值永远不会直接设置，只能通过UserDefaults

设置。

使计时器的变量等于UserDefaults

1 个答案: