iOS/swift之进入前后台通知

 //注册进入前台的通知
        NotificationCenter.default.addObserver(self, selector:#selector(becomeActive), name: UIApplication.didBecomeActiveNotification, object: nil)
        //注册进入后台的通知
        NotificationCenter.default.addObserver(self, selector:#selector(becomeDeath), name: UIApplication.willResignActiveNotification, object: nil)
       
  
   
   
    //必须要加@objc-----进入前台
    @objc  func becomeActive(noti:Notification){
        
        print("进入前台")
    }
    //必须要加@objc----进后台
    @objc  func becomeDeath(noti:Notification){
        
        print("进入后台")
    }