.isHidden 属性即使在使用 view.setNeedsDisplay() 刷新视图后也不会反映对视图的更改

Question

收到应用程序委托后，我传递了一个静态字符串并刷新了电影详细信息ViewController 使用设置需要布局，函数和代码工作正常，但更改没有反映在视图中。

AppDelegate：-

let storyboard = UIStoryboard(name: "Main", bundle: nil)
                    let movieDetailsVC = storyboard.instantiateViewController(withIdentifier: "MovieDetailsViewController") as! MovieDetailsViewController




                        if (rootViewController?.isKind(of: MovieDetailsViewController.self))!
                        {
                            if notificationContentType == 1
                            {
                                movieDetailsVC.FROMPAGE = "FROMAPPDELEGATE"
                                movieDetailsVC.view.setNeedsDisplay()
                            }
                        }

ViewController:-

override func viewDidLoad()
    {
        super.viewDidLoad()

        let appDelegate: AppDelegate? = UIApplication.shared.delegate as? AppDelegate
        appDelegate?.read()

        if FROMPAGE == "FROMAPPDELEGATE"
        {
//                self.updateUI()
            print("Function is Called")
            //print(self.view.frame)
            //self.view.setNeedsDisplay()

            let appDelegate: AppDelegate? = UIApplication.shared.delegate as? AppDelegate
            appDelegate?.read()


            var currentreleaseId : Int!
            var currentrentalType : Int!

            currentreleaseId = resultDictionaryFromFCM.value(forKey: "releaseId") as? Int
            let convertedId = String(currentreleaseId)
            currentrentalType = resultDictionaryFromFCM.value(forKey: "rentalType") as? Int
            let elapsedTime = resultDictionaryFromFCM.value(forKey: "elapsedTime") as? Float

            if convertedId == ApiClassStruct.RELEASEID
            {
                let movieStartDate = resultDictionaryFromFCM.value(forKey: "clientStartTime") as? Double
                defaults.set(movieStartDate, forKey: "MOVIE_START_DATE")
                if currentrentalType == 1
                {
                    defaults.set("true", forKey: "isStillPlaying")
                    self.tableViewOutlet.isHidden = true
                    self.seekBarOutlet.isHidden = false


                    let maximumDuration = defaults.integer(forKey: "MAXIMUMDURATION")
                    self.seekBarMaximumDurationLabelOutlet.text = self.convertTime(miliseconds: maximumDuration)
                    self.seekBarOutlet.maximumValue = Float(maximumDuration)

                    let currentDate = NSDate()
                    let dateFormatter = DateFormatter()
                    dateFormatter.dateFormat = "yyyy-MM-dd, HH:mm:ss"
                    dateFormatter.timeZone = NSTimeZone(name: "IST") as TimeZone!
                    let date = dateFormatter.date(from: dateFormatter.string(from: currentDate as Date))
                    let currentDATE = date!.timeIntervalSince1970 * 1000

                    let movieStartDate = defaults.value(forKey: "MOVIE_START_DATE") as? Double

                    let difference = currentDATE - movieStartDate!

                    self.seekBarOutlet.setValue(Float(difference), animated: true)
                    let selectedValue = "\(Int(self.seekBarOutlet.value))"
                    let convertedValue = self.convertTime(miliseconds: Int(selectedValue)!)
                    self.seekBarMinimumDurationLabelOutlet.text = convertedValue

                    self.myTimer =  Timer.scheduledTimer(timeInterval:1, target: self, selector: #selector(self.updateSlider), userInfo: nil, repeats: true)

                    print("Play condition ended")
                }
}

但是修改后没有反应，卡在这个问题很久了

Answer 1

let movieDetailsVC = storyboard.instantiateViewController(withIdentifier: "MovieDetailsViewController") as! MovieDetailsViewController

创建 MovieDetailsViewController 的新实例并对其进行修改。如果您不提供该实例，则不会看到任何更改。如果您已经提交了MovieDetailsViewController个实例，则提交的实例将不受其影响。

我建议使用通知来通知 MovieDetailsViewController 更新其 UI。

例如，在应用委托中使用它来创建和post一个新的通知：

NotificationCenter.default.post(name: NSNotification.Name("movieDetailsUpdateNotif"),
                                object: self, userInfo: nil)

然后在 MovieDetailsViewController.viewDidLoad 中注册以收听这些通知：

override func viewDidLoad() {
    super.viewDidLoad()

    NotificationCenter.default.addObserver(self,
                                           selector: #selector(receiveNotification(notification:)),
                                           name: NSNotification.Name("movieDetailsUpdateNotif"),
                                           object: nil)
}

要清理它，请在 deinit 中注销（只是为了表现得很好）：

deinit {
    NotificationCenter.default.removeObserver(self)
}

最后，实现MovieDetailsViewController.receiveNotification(notification:)来处理通知：

@objc fileprivate func receiveNotification(notification: NSNotification) {
    // update UI here, e.g. hide things, show other, etc.
    // this will be called when AppDelegate creates a and posts that notification
}

.isHidden 属性即使在使用 view.setNeedsDisplay() 刷新视图后也不会反映对视图的更改

.isHidden property does not reflect changes to the view even after refreshing the view using view.setNeedsDisplay()

view

ios

swift

swift3

.isHidden 属性 即使在使用 view.setNeedsDisplay() 刷新视图后也不会反映对视图的更改

.isHidden property does not reflect changes to the view even after refreshing the view using view.setNeedsDisplay()

view

ios

swift

swift3

.isHidden 属性即使在使用 view.setNeedsDisplay() 刷新视图后也不会反映对视图的更改