生命周期
// 加载视图时会调用该方法
override func loadView() {
super.loadView()
print("加载视图")
}
// 当加载视图结束时调用该方法
override func viewDidLoad() {
super.viewDidLoad()
print("加载视图结束")
// 监听应用进入前后台
NotificationCenter.default.addObserver(self, selector: #selector(appWillEnterForeground), name: UIApplication.willEnterForegroundNotification, object: nil)
NotificationCenter.default.addObserver(self, selector: #selector(appDidEnterBackground), name: UIApplication.didEnterBackgroundNotification, object: nil)
}
// 视图将要显示时调用该方法
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
print("视图即将显示")
}
// 当视图已经显示时调用该方法
override func viewDidAppear(_ animated: Bool) {
super.viewDidAppear(animated)
print("视图已经显示")
}
// 当视图将要消失时调用该方法
override func viewWillDisappear(_ animated: Bool) {
super.viewWillDisappear(animated)
print("视图即将消失")
}
// 当时图已经消失时调用该方法
override func viewDidDisappear(_ animated: Bool) {
super.viewDidDisappear(animated)
print("视图已经消失")
}
// 当接收到内存警告时会执行这个方法
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
// 将进入前台通知
@objc func appWillEnterForeground(){
print("周期 ---将进入前台通知")
}
//应用程序确实进入了后台
@objc func appDidEnterBackground(){
print("周期 ---应用程序确实进入了后台")
}
