How do you implement headers in a UICollectionView
? I know you can put in supplementary views, but I don\'t know how to make them \"float\" above a section like hea
Update for iOS9:
let flow = collectionView.collectionViewLayout as! UICollectionViewFlowLayout
flow.sectionHeadersPinToVisibleBounds = true
Pass it along.
EDIT: As mentioned in the comments, this answer is valid, but not for multiple sections. See this blog for a better solution: http://blog.radi.ws/post/32905838158/sticky-headers-for-uicollectionview-using#notes
You need to specify that behaviour in your layout:
- (NSArray *)layoutAttributesForElementsInRect:(CGRect)rect
{
NSMutableArray* attributesArray = [[super layoutAttributesForElementsInRect:rect] mutableCopy];
BOOL headerVisible = NO;
for (UICollectionViewLayoutAttributes *attributes in attributesArray) {
if ([attributes.representedElementKind isEqualToString:UICollectionElementKindSectionHeader]) {
headerVisible = YES;
attributes.frame = CGRectMake(self.collectionView.contentOffset.x, 0, self.headerReferenceSize.width, self.headerReferenceSize.height);
attributes.alpha = HEADER_ALPHA;
attributes.zIndex = 2;
}
}
if (!headerVisible) {
UICollectionViewLayoutAttributes *attributes = [self layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionHeader
atIndexPath:[NSIndexPath
indexPathForItem:0
inSection:0]];
[attributesArray addObject:attributes];
}
return attributesArray;
}