在布局之前调用 invalidateLayout 是解决此问题的方法.

Calling invalidateLayout before layout is a workaround for this issue.

在 UIViewController 子类中:

override func viewWillLayoutSubviews() {
    super.viewWillLayoutSubviews()
    collectionView.collectionViewLayout.invalidateLayout()
}

或在 UIView 子类中:

override func layoutSubviews() {
    super.layoutSubviews()
    collectionView.collectionViewLayout.invalidateLayout()
}