iOS，子视图大小无缘无故变化

Question

 @objc class SearchViewController: UIViewController {

     var uiView: UIView!

     @IBOutlet weak var reactWrapperView: UIView!

     override func viewDidLoad() {
         super.viewDidLoad()


         self.view.layer.borderColor = UIColor.yellow.cgColor
         self.view.layer.borderWidth = 2

         self.reactWrapperView.frame = (self.reactWrapperView.superview?.bounds)!
         self.reactWrapperView.layer.borderColor = UIColor.red.cgColor
         self.reactWrapperView.layer.borderWidth = 5

         self.uiView = UIView(frame: (self.reactWrapperView.superview?.bounds)!)
         self.uiView.layer.borderColor = UIColor.blue.cgColor
         self.uiView.layer.borderWidth = 10

         self.reactWrapperView.addSubview(self.uiView)

     }
 }

self.view和self.rectWrapperView在故事板中创建，它们与手机屏幕大小相同，如下图所示。

self.view : yellow
self.reactWrapperView : red
self.uiView: blue

如您所见，未显示底部蓝色边框，uiView似乎在增大。

我一直在苦苦挣扎很长时间，想知道什么会影响尺寸。

Answer 1

可能原因是：

     self.uiView = UIView(frame: (self.uiView.superview?.bounds)!)

你是否已经将uiview添加到someView？否则，为什么这个uiview有超级视图？

Answer 2

您的Viewcontroller UI未更新（表示未完全加载），您可以移入主线程，还是将代码移至 viewwillappear 或 viewDidAppear ，原因ui没有更新。

<强>选项1

override func viewDidLoad() {
         super.viewDidLoad()

         DispatchQueue.main.async { // or use sync


         self.view.layer.borderColor = UIColor.yellow.cgColor
         self.view.layer.borderWidth = 2

         self.reactWrapperView.frame = (self.reactWrapperView.superview?.bounds)!
         self.reactWrapperView.layer.borderColor = UIColor.red.cgColor
         self.reactWrapperView.layer.borderWidth = 5

         self.uiView = UIView(frame: (self.reactWrapperView.superview?.bounds)!)
         self.uiView.layer.borderColor = UIColor.blue.cgColor
         self.uiView.layer.borderWidth = 10

         self.reactWrapperView.addSubview(self.uiView)

     }
    }
 }

<强>选项2

 override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)


         self.view.layer.borderColor = UIColor.yellow.cgColor
         self.view.layer.borderWidth = 2

         self.reactWrapperView.frame = (self.reactWrapperView.superview?.bounds)!
         self.reactWrapperView.layer.borderColor = UIColor.red.cgColor
         self.reactWrapperView.layer.borderWidth = 5

         self.uiView = UIView(frame: (self.reactWrapperView.superview?.bounds)!)
         self.uiView.layer.borderColor = UIColor.blue.cgColor
         self.uiView.layer.borderWidth = 10

         self.reactWrapperView.addSubview(self.uiView)

     }
 }