ios7 - UICollectionView + iOS 7/Xcode 5 = 断言失败

Question

在我的应用程序中，有一个 UICollectionView 使用 flowLayout，它在 iOS 6 中运行良好，但在 iOS 7 中失败了。一旦我转到包含我的 UICollectionView 的 View ，就会发生以下情况:

*** Assertion failure in -[UICollectionView _createPreparedSupplementaryViewForElementOfKind:atIndexPath:withLayoutAttributes:applyAttributes:], /SourceCache/UIKit/UIKit-2903.2/UICollectionView.m:1401
*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'the view returned from -collectionView:viewForSupplementaryElementOfKind:atIndexPath
(UICollectionElementKindSectionHeader,<NSIndexPath: 0x145f3f50> {length = 2, path = 0 - 0}) was not retrieved by calling -dequeueReusableSupplementaryViewOfKind:withReuseIdentifier:forIndexPath: or is nil'
(<UICollectionReusableView: 0x145f9400; frame = (0 0; 320 20); layer = <CALayer: 0x145f90c0>>)

Answer 1

当我更新到 iOS 7 时，我遇到了这个问题。问题最终是你不应该对你的数据源如此明确。如果您有以下情况，请将其删除:

- (UICollectionReusableView *)collectionView:(UICollectionView *)collectionView viewForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath {
    return nil;
}