参考preferredStatusBarUpdateAnimation，

Gif

码

class ViewController: UIViewController {
    var isHidden:Bool = false{
        didSet{
            UIView.animate(withDuration: 0.5) { () -> Void in
                self.setNeedsStatusBarAppearanceUpdate()
            }  
         }
    }
    @IBAction func clicked(sender: AnyObject) {
        isHidden = !isHidden
    }
    override var preferredStatusBarUpdateAnimation: UIStatusBarAnimation{
        return .slide
    }
    override var prefersStatusBarHidden: Bool{
        return isHidden
    }
 }