UICollectionViewFlowLayout has cached frame mismatch

This is likely occurring because the flow layout subclass MyLineLayout is modifying attributes returned by UICollectionViewFlowLayout without copying them

- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect

NSArray *original = [super layoutAttributesForElementsInRect:rect];

NSArray *array = [[NSArray alloc] initWithArray:original copyItems:YES];

对array进行修改就可以了，不要对original修改

这样就不会报这个警告了