Adjusting the top layout guide of a view controller

If your content view controller depends on the top layout guide being adjusted — e.g. if the content does not have a tracking scroll view and therefore relies on the top layout guide to perform layout calculations — then you should consider setting topLayoutGuideViewController to the content view controller.

Setting this property does two things:

1. Adjusts the view controller's topLayoutGuide property to take the flexible header into account (most useful pre-iOS 11).
2. On iOS 11 and up — if there is no tracking scroll view — also adjusts the additionalSafeAreaInsets property to take the flexible header into account.

Note: topLayoutGuideAdjustmentEnabled is automatically enabled if this property is set.

Swift

flexibleHeaderViewController.topLayoutGuideViewController = contentViewController

Objective-C

flexibleHeaderViewController.topLayoutGuideViewController = contentViewController;