willappear-skip-1.swift

    // Using RxSwift
    override func viewDidLoad() {
        super.viewDidLoad()
        rx.sentMessage(#selector(viewWillAppear(_:)))
            .skip(1)
            .subscribe(onNext: {
                self.doSomething()
            })
            .disposed(by: rx_disposeBag)
        rx.sentMessage(#selector(viewDidLayoutSubviews))
            .take(1)
            .subscribe(onNext: {
                self.doSomething()
            })
            .disposed(by: rx_disposeBag)
    }