在我的界面上有一個(gè)加在keyWindow上的按鈕。想在側(cè)滑返回的時(shí)候像導(dǎo)航欄漸變消失。效果如下

2017-03-09 17_23_30.gif

核心代碼

navigationController?.interactivePopGestureRecognizer?.addTarget(self, action: #selector(action))

func action(sender: UIScreenEdgePanGestureRecognizer) {
        switch sender.state {
        case .changed:
            let x = sender.translation(in: view).x
            let progress = 1 - x / view.frame.width
            postButton.alpha = progress
        default:
            UIView.animate(withDuration: 0.4) {
                self.postButton.alpha = 1
            }
        }
    }

Demo