iOS-自动版面轮换无法正常运作

Question

I have app with enabled rotation for iPad (iPhone version is rotation-free). In my design, within storyboard, I have this hierarchy: UIView - UIScrollView - UIView . All "views" are set to have full width of the screen. Second UIView has class set to MyView , which is a class with an external xib file. Storyboard and xib are both created in a portrait mode.

Now for the problem.

• If I run the app in the landscape mode, all is loaded OK. If I rotate app after that, all is OK.

• If I run the app in the portrait mode, the design "breaks". The entire content is thiner (so there is about 100+ px gap between the end of MyView and the end of the screen). If I rotate app, the design remains broken but correctly "enlarged". The gap is still of the same size. During the first launch, I got the following error in debugger:

   Unable to simultaneously satisfy constraints. Probably at least one of the constraints in the following list is one you don't want. Try this: (1) look at each constraint and try to figure out which you don't expect; (2) find the code that added the unwanted constraint or constraints and fix it. (Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints) ( "<NSAutoresizingMaskLayoutConstraint:0x1545b7800 h=-&- v=-&- UIView:0x1546a8cb0.width == ScrollableContentView:0x154575da0.width - 232>", "<NSLayoutConstraint:0x15458dd80 H:[UIActivityIndicatorView:0x1546afa60]-(370)-| (Names: '|':UIView:0x1546ab840 )>", "<NSLayoutConstraint:0x15458ddd0 H:|-(361)-[UIActivityIndicatorView:0x1546afa60] (Names: '|':UIView:0x1546ab840 )>", "<NSLayoutConstraint:0x1546c7080 H:[UIView:0x1546ab840]-(0)-| (Names: '|':UIView:0x1546a8cb0 )>", "<NSLayoutConstraint:0x1546c7120 H:|-(0)-[UIView:0x1546ab840] (Names: '|':UIView:0x1546a8cb0 )>", "<NSLayoutConstraint:0x154579710 H:|-(0)-[ScrollableContentView:0x154575da0] (Names: '|':UIScrollView:0x15504c000 )>", "<NSLayoutConstraint:0x154686ef0 UIScrollView:0x15504c000.centerX == ScrollableContentView:0x154575da0.centerX>", "<NSLayoutConstraint:0x154697cc0 H:[UIScrollView:0x15504c000]-(0)-| (Names: '|':UIView:0x154547b80 )>", "<NSLayoutConstraint:0x154697d10 H:|-(0)-[UIScrollView:0x15504c000] (Names: '|':UIView:0x154547b80 )>", "<NSLayoutConstraint:0x15463b8c0 'UIView-Encapsulated-Layout-Width' H:[UIView:0x154547b80(768)]>" ) Will attempt to recover by breaking constraint 

No matter what I do, I am unable to remove this problem. Even If I deleted almost every constraint I have still the same issue.

Answer 1

You should look if you don't have any auto layout warnings in your storyboard or xib file (yellow/red dot beside your controller name in document outline).

If you don't have any, do you set your constraints when adding your xib view ?

Have you think about content hugging priority or content compression resistance priority ?