从特定的UIViewController识别applicationDidBecomeActive

Question

我想知道是否有一种方法或方法可用于操作一段代码，并且从后台调用app并变为活动状态。我需要从视图本身开始工作，而不是应用委托

Answer 1

当您需要在从后台唤醒时在视图控制器中执行某些操作时，您必须使用 UIApplicationDidBecomeActiveNotification 的侦听器

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    NotificationCenter.default.addObserver(self, selector: #selector(self.executeMethod), name: NSNotification.Name.UIApplicationDidBecomeActive, object: nil)
}

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    NotificationCenter.default.removeObserver(self, name: NSNotification.Name.UIApplicationDidBecomeActive, object: nil)
}

func executeMethod()  {
    // execute your code here
}