Custom UICollectionViewCell Auto Layout NSInternalInconsistencyException error

Question

I'm subclassing a UICollectionViewCell and doing all the layout in code with auto layout. This is my init method:

- (id)initWithFrame:(CGRect)frame{
    frame = CGRectMake(0, 0, 403, 533);
    if (self = [super initWithFrame:frame]) {
        self.translatesAutoresizingMaskIntoConstraints = NO;

        PBCardPricesViewController *pricesView = [[PBCardPricesViewController alloc] init];
        [self addSubview:pricesView.view];

        UIImageView *background = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"CardBackground"]];
        [self addSubview:background];

        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|-(20)-[background]|" options:0 metrics:nil views:@{@"background":background}]];
        [self addConstraint:[NSLayoutConstraint constraintWithItem:pricesView.view attribute:NSLayoutAttributeLeft relatedBy:NSLayoutRelationEqual toItem:background attribute:NSLayoutAttributeLeft multiplier:1 constant:0]];

        [self addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[background]|" options:0 metrics:nil views:@{@"background":background}]];
        [self addConstraint:[NSLayoutConstraint constraintWithItem:pricesView.view attribute:NSLayoutAttributeTop relatedBy:NSLayoutRelationEqual toItem:background attribute:NSLayoutAttributeTop multiplier:1 constant:0]];
    }

    return self;
}

When I comment out the translateAutoresizingMask line I get:

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) 

(

    "<NSLayoutConstraint:0x1d83f540 H:[UIImageView:0x1d83f950]-(0)-|   (Names: '|':PBCardViewCollectionCell:0x1d83b970 )>",

    "<NSAutoresizingMaskLayoutConstraint:0x1c55ad20 h=--& v=--& H:[PBCardViewCollectionCell:0x1d83b970(393)]>",

    "<NSAutoresizingMaskLayoutConstraint:0x1c559410 h=--& v=--& UIImageView:0x1d83f950.midX == + 191.5>",

    "<NSAutoresizingMaskLayoutConstraint:0x1c559450 h=--& v=--& H:[UIImageView:0x1d83f950(383)]>"

)



Will attempt to recover by breaking constraint 

<NSLayoutConstraint:0x1d83f540 H:[UIImageView:0x1d83f950]-(0)-|   (Names: '|':PBCardViewCollectionCell:0x1d83b970 )>



Break on objc_exception_throw to catch this in the debugger.

The methods in the UIConstraintBasedLayoutDebugging category on UIView listed in <UIKit/UIView.h> may also be helpful.

When I don't I get this error: Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Auto Layout still required after executing -layoutSubviews. UICollectionView's implementation of -layoutSubviews needs to call super.' How do I get this to show the way I want it to? What am I missing?

Answer 1

Posting my comment as the answer:

In my experiences, collectionViewCells (and tableViewCells) require their autoresizingmask or they throw the exception you see. But you are getting constraint conflicts due to the subviews you added, so just remove the mask from its subviews:

backgroundView.translatesAutoresizingMaskIntoConstraints = NO;  
pricesView.view.translatesAutoresizingMaskIntoConstraints = NO; // you might get it to work without doing this line

I also try to remember to remove the mask on views I create using alloc (ie not from a xib), since most of the time they give conflicts.