ios swift 判断uiviewcontroller时push present 进来的 还是pop进来的

override func viewWillAppear(_ animated: Bool) {

        super.viewWillAppear(animated)

        //显示navbar

        self.navigationController?.setNavigationBarHidden(false, animated: true)

        if(isBeingPresented || isMovingToParent){

            print("======push")

        }else{

            print("======pop")

        }

    }