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    <p>Either implement the following delegate methods:</p> <pre><code>– collectionView:layout:sizeForItemAtIndexPath: – collectionView:layout:insetForSectionAtIndex: – collectionView:layout:minimumLineSpacingForSectionAtIndex: – collectionView:layout:minimumInteritemSpacingForSectionAtIndex: – collectionView:layout:referenceSizeForHeaderInSection: – collectionView:layout:referenceSizeForFooterInSection: </code></pre> <p>In your view controller that has your <code>:cellForItemAtIndexPath</code> method (just return the correct values). Or, instead of using the delegate methods, you may also set these values directly in your layout object, e.g. <code>[layout setItemSize:size];</code>.</p> <p>Using either of these methods will enable you to set your settings in Code rather than IB as they're removed when you set a Custom Layout. Remember to add <code>&lt;UICollectionViewDelegateFlowLayout&gt;</code> to your .h file, too!</p> <p>Create a new Subclass of <code>UICollectionViewFlowLayout</code>, call it whatever you want, and make sure the H file has:</p> <pre><code>#import &lt;UIKit/UIKit.h&gt; @interface YourSubclassNameHere : UICollectionViewFlowLayout @end </code></pre> <p>Inside the Implementation File make sure it has the following:</p> <pre><code>- (NSArray *) layoutAttributesForElementsInRect:(CGRect)rect { NSMutableArray *answer = [[super layoutAttributesForElementsInRect:rect] mutableCopy]; UICollectionView * const cv = self.collectionView; CGPoint const contentOffset = cv.contentOffset; NSMutableIndexSet *missingSections = [NSMutableIndexSet indexSet]; for (UICollectionViewLayoutAttributes *layoutAttributes in answer) { if (layoutAttributes.representedElementCategory == UICollectionElementCategoryCell) { [missingSections addIndex:layoutAttributes.indexPath.section]; } } for (UICollectionViewLayoutAttributes *layoutAttributes in answer) { if ([layoutAttributes.representedElementKind isEqualToString:UICollectionElementKindSectionHeader]) { [missingSections removeIndex:layoutAttributes.indexPath.section]; } } [missingSections enumerateIndexesUsingBlock:^(NSUInteger idx, BOOL *stop) { NSIndexPath *indexPath = [NSIndexPath indexPathForItem:0 inSection:idx]; UICollectionViewLayoutAttributes *layoutAttributes = [self layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionHeader atIndexPath:indexPath]; [answer addObject:layoutAttributes]; }]; for (UICollectionViewLayoutAttributes *layoutAttributes in answer) { if ([layoutAttributes.representedElementKind isEqualToString:UICollectionElementKindSectionHeader]) { NSInteger section = layoutAttributes.indexPath.section; NSInteger numberOfItemsInSection = [cv numberOfItemsInSection:section]; NSIndexPath *firstCellIndexPath = [NSIndexPath indexPathForItem:0 inSection:section]; NSIndexPath *lastCellIndexPath = [NSIndexPath indexPathForItem:MAX(0, (numberOfItemsInSection - 1)) inSection:section]; NSIndexPath *firstObjectIndexPath = [NSIndexPath indexPathForItem:0 inSection:section]; NSIndexPath *lastObjectIndexPath = [NSIndexPath indexPathForItem:MAX(0, (numberOfItemsInSection - 1)) inSection:section]; UICollectionViewLayoutAttributes *firstObjectAttrs; UICollectionViewLayoutAttributes *lastObjectAttrs; if (numberOfItemsInSection &gt; 0) { firstObjectAttrs = [self layoutAttributesForItemAtIndexPath:firstObjectIndexPath]; lastObjectAttrs = [self layoutAttributesForItemAtIndexPath:lastObjectIndexPath]; } else { firstObjectAttrs = [self layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionHeader atIndexPath:firstObjectIndexPath]; lastObjectAttrs = [self layoutAttributesForSupplementaryViewOfKind:UICollectionElementKindSectionFooter atIndexPath:lastObjectIndexPath]; } CGFloat headerHeight = CGRectGetHeight(layoutAttributes.frame); CGPoint origin = layoutAttributes.frame.origin; origin.y = MIN( MAX( contentOffset.y + cv.contentInset.top, (CGRectGetMinY(firstObjectAttrs.frame) - headerHeight) ), (CGRectGetMaxY(lastObjectAttrs.frame) - headerHeight) ); layoutAttributes.zIndex = 1024; layoutAttributes.frame = (CGRect){ .origin = origin, .size = layoutAttributes.frame.size }; } } return answer; } - (BOOL) shouldInvalidateLayoutForBoundsChange:(CGRect)newBound { return YES; } </code></pre> <p>Choose "Custom" in Interface Builder for the Flow Layout, choose your "YourSubclassNameHere" Class that you just created. And Run!</p> <p>(Note: the code above may not respect contentInset.bottom values, or especially large or small footer objects, or collections that have 0 objects but no footer.)</p>
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    1. POHow to make Supplementary View float in UICollectionView as Section Headers do in UITableView plain style
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    1. UStopLayoutGuide
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    1. COThis worked perfectly. Thanks!
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      1. USFrank Schmitt
    2. COIf `numberOfItemsInSection == 0`, you will get a `EXC_ARITHMETIC code=EXC_I386_DIV` (divide-by-zero?) crash on this line: `UICollectionViewLayoutAttributes *firstCellAttrs = [self layoutAttributesForItemAtIndexPath:firstCellIndexPath];`. I've also noticed that the `contentOffset` parts of this code are not respecting the collection view's top-inset value in my implementation (may be related to the previous issue).. Will propose a code change/gist/etc.
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    3. COhttps://gist.github.com/toblerpwn/5393460 - feel free to iterated, particularly on the limitations noted in the gist. :)
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Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

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