Why UIView is wider than Screen

Question

I've created a view controller using interface builder, while size classes is on.

the view has leading and trailing constraints to it's super view which is the view controller's view. something like this.

|-(14)-(view)-(14)-|

When i'm running the app it looks great, the view has those 14pt insets on both sides, though when I print it's width I get 576 which is wider than the screen width. In interface builder the view's frame width is set to 576 (as the canvas size when size classes is on) but at run time the constraints should override this I guess.

How come the view appears right, but it's frame shows a bigger width ??

Answer 1

When did you print the width ?. I guess in ViewDidLoad. Because you use Interface Builder and enable size classes, so by default, the width and height are 600x600. At the time view did load, the size still refer the size from Interface builder until view did appear, it will be automatically scaled according to the screen size. That why your UIView is wider than the screen.

Here is what I printed out from a view controller built using Interface builder and enable size classes. Run on iPhone 6S plus

[Size] at view did load {{0, 0}, {600, 600}}

[Size] at view did appear {{0, 64}, {414, 623}}