the behavior of the UICollection

the behavior of the UICollectionViewFlowLayout is not defined because:

** the item height must be less than the height of the UICollectionView minus the section insets top and bottom values, minus the content insets top and bottom values.**

The relevant UICollectionViewFlowLayout instance is <UICollectionViewFlowLayout: 0x7fabf9580f60>, and it is attached to <UICollectionView: 0x7fabf9875800; frame = (0 0; 320 125); clipsToBounds = YES; autoresize = RM+BM; gestureRecognizers = <NSArray: 0x7fabf9573f70>; layer = <CALayer: 0x7fabf95769d0>; contentOffset: {0, 0}; contentSize: {0, 125}> collection view layout: <UICollectionViewFlowLayout: 0x7fabf9580f60>.

Make a symbolic breakpoint at UICollectionViewFlowLayoutBreakForInvalidSizes to catch this in the debugger.

解决方法

• (void)viewDidLoad {
  [super viewDidLoad];
  //UICollectionViewController的属性
  self.automaticallyAdjustsScrollViewInsets = NO;
  }