识别应用程序DidBecomeActive from a specific UIViewController

Question

我想知道是否有一种方法或方法可以用来操作一段代码，当应用程序从后台调用并变为活动状态时。我需要该方法从视图本身而不是应用程序委托工作

Answer 1

当你需要在后台唤醒时在视图控制器中执行一些操作时，你必须使用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
}