Error: Exception NSException * "the view returned from -collectionView:viewForSupplementaryElement

Question

谁能帮我指出我哪里错了？我的应用因以下错误而崩溃：

Thread 1: 

Exception: "the view returned from -collectionView:viewForSupplementaryElementOfKind:atIndexPath (UICollectionElementKindSectionHeader,
<NSIndexPath: 0x8180a74d626573ba> {length = 2, path = 0 - 0}) 
was not retrieved by calling -dequeueReusableSupplementaryViewOfKind:withReuseIdentifier:forIndexPath: or is nil 

(<UICollectionReusableView: 0x7fd9fbecc400; frame = (0 0; 0 0); layer = <CALayer: 0x6000028c7f60>>)"

方法在这里

func collectionView(_ collectionView: UICollectionView, viewForSupplementaryElementOfKind kind: String, at indexPath:
            IndexPath) -> UICollectionReusableView {
            
            guard kind == UICollectionView.elementKindSectionFooter else {
                // footer
            return UICollectionReusableView()
            }
            
            if indexPath.section == 1 {
                // tabs header
                let tabControlHeader = collectionView.dequeueReusableSupplementaryView(ofKind: kind,
                                                                                       withReuseIdentifier: ProfileTabsCollectionReusableView.identifier,
                                                                                       for: indexPath) as! ProfileTabsCollectionReusableView
                return tabControlHeader
    
            }
            
            let profileHeader = collectionView.dequeueReusableSupplementaryView(ofKind: kind,
                                                                                withReuseIdentifier: ProfileInfoHeaderCollectionReusableView.identifier,
                                                                                for: indexPath) as! ProfileInfoHeaderCollectionReusableView
            return profileHeader
        }

Answer 1

错误这样读起来更好

the view returned from 
-collectionView:viewForSupplementaryElementOfKind:atIndexPath
was 

either
not retrieved by calling 
-dequeueReusableSupplementaryViewOfKind:withReuseIdentifier:forIndexPath: 

or 
is nil

查看以下代码return问题所在。

return UICollectionReusableView()

在 guard else 早期 return 块内放置一个断点。决定是否要从那里 return dequeued 页眉或页脚。

您必须 return 使用 collectionView.dequeueXXX 调用实例化的页眉/页脚，而不是您自己创建的东西。

Answer 2

我通过更改解决了这个错误

guard kind == UICollectionView.elementKindSectionFooter else {
                // footer
            return UICollectionReusableView()
            }

到

guard kind == UICollectionView.elementKindSectionHeader else {
                // footer
            return UICollectionReusableView()
            }

还要确保在 Main.storyboard 中每个 View Controller

都检查了 Inherit Module From Target

Error: Exception NSException * "the view returned from -collectionView:viewForSupplementaryElement

Error: Exception NSException * "the view returned from -collectionView:viewForSupplementaryElement

ios

uicollectionview

swift

swift5