问题
In viewDidLoad func of my UIViewController I call
print("\(UIScreen.main.bounds.size.width) \(collectionView.frame.width)")
and it prints
320.0 375.0
How is it possible? UICollectionView should has the same width, mb smaller but definitely not bigger
Settings of this view in storyboard:
each constraint set as
So I test it on iPhone SE Simulator but in Storyboard I have iPhone 8.
But I believe it should not matter at all when I use autolayout (constraints to make size of my view match size of safe area)
iPhone 8 width is 375 points and iPhone SE is 320:
Update
It seems viewDidLoad returns sizes of your last selected device in storyboard (quite ugly)
So to get correct data about views I have to get sizes in viewDidAppear
In Android if size of some view isn't available yet (view wasn't inflated yet) then it just returns zeros (width == 0, height == 0), but in iOS you get width and height from Xcode Storyboard in runtime... Really?
回答1:
When you're instantiating a view controller from storyboard, the size of its view will be what is currently set on the storyboard. It will have the same size as the screen after it has been added to the view hierarchy. viewDidLoad is called before the view is added so it will still have the same size as on the storyboard. You can get the size it is displayed in inside methods, viewWillApear, viewDidAppear, and viewDidLayout. Just keep in mind that these methods might be called multiple times.
来源：https://stackoverflow.com/questions/55667820/frame-size-of-uicollectionview-is-bigger-than-size-of-uiscreen