在滚动视图中加载的视图大小不正确

Question

我将 3 个视图加载到滚动视图中，以便用户可以在应用中滑动以更改视图（类似于 Snapchat 或 Tinder 导航）。但是，我在其中一个笔尖上添加了一个水平和垂直居中的标签，它看起来好像比我的屏幕宽得多。我将笔尖框架设置为设备屏幕的大小。

如何使子视图匹配视图的框架（全屏）？

这是我在 viewDidLoad 中为带有全屏滚动视图的视图控制器提供的内容，以及结果的屏幕截图：

@IBOutlet weak var scrollViewOfViews: UIScrollView!

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
    let settingsVC = UIViewController(nibName: "SettingsViewController", bundle: nil)
    let friendsFeedVC = UIViewController(nibName: "FriendsFeedViewController", bundle: nil)
    let notificationsVC = UIViewController(nibName: "NotificationsViewController", bundle: nil)

    let screenSize = UIScreen.mainScreen().bounds
    settingsVC.view.frame = screenSize
    friendsFeedVC.view.frame = screenSize
    notificationsVC.view.frame = screenSize

    self.addChildViewController(settingsVC)
    self.scrollViewOfViews.addSubview(settingsVC.view)
    settingsVC.didMoveToParentViewController(self)

    self.addChildViewController(friendsFeedVC)
    self.scrollViewOfViews.addSubview(friendsFeedVC.view)
    friendsFeedVC.didMoveToParentViewController(self)

    self.addChildViewController(notificationsVC)
    self.scrollViewOfViews.addSubview(notificationsVC.view)
    notificationsVC.didMoveToParentViewController(self)

    var friendsFeedFrame = friendsFeedVC.view.frame
    friendsFeedFrame.origin.x = self.view.frame.width
    friendsFeedVC.view.frame = friendsFeedFrame

    var notificationsFrame = notificationsVC.view.frame
    notificationsFrame.origin.x = self.view.frame.width * 2
    notificationsVC.view.frame = notificationsFrame

    self.scrollViewOfViews.contentSize = CGSize(width: self.view.frame.width * 3, height: self.view.frame.size.height)

    // start scrollview page on middle view
    var startFrame = scrollViewOfViews.frame
    startFrame.origin.x = self.view.frame.width
    startFrame.origin.y = 0
    scrollViewOfViews.scrollRectToVisible(startFrame, animated: false)

}

带有居中标签的friendsFeedVC的结果：

Answer 1

“你不应该在viewDidLoad初始化UI几何相关的东西，因为你的视图的几何此时没有设置，结果会不可预知”

“viewWillAppear: 是做这些事情的正确位置，此时几何已设置好，因此获取和设置与几何相关的属性是有意义的。”

或者您可以将它们设置在viewDidLayoutSubviews

尝试将设置视图框架的代码放在viewWillAppear或viewDidLayoutSubviews中

参考：Why am I having to manually set my view's frame in viewDidLoad?