ios - 当 View Controller 被关闭时，补充 View 会短暂保留

Question

我在 Collection View 的顶部添加了一个 View ，现在当我关闭 View 时，该 View 会保留一瞬间。有谁知道可能导致这种情况的原因吗？

let newView = UIView() newView.backgroundColor = UIColor.redColor() 

newView.translatesAutoresizingMaskIntoConstraints = false view.addSubview(newView) 

let pinTop = NSLayoutConstraint(item: newView, attribute: .Top, relatedBy: .Equal, toItem: 

self.topLayoutGuide, attribute: .Bottom, multiplier: 1.0, constant: 0) 

let heightConstraint = newView.heightAnchor.constraintEqualToAnchor(nil, constant: 50) 

let widthConstraint = NSLayoutConstraint(item: newView, attribute: .Width, relatedBy: .Equal, toItem: view, attribute: .Width, multiplier: 1.0, constant: 0) 

self.topContentAdditionalInset = 50 

NSLayoutConstraint.activateConstraints([pinTop, heightConstraint, widthConstraint])

Answer 1

如果您使用 viewController 关闭它，请尝试在 viewWillDissapear 中添加 newView .removeFromSuperview() 并在 viewWillAppear 中重新添加它