"no UICollectionViewLayoutAttributes instance"是什么意思？

Question

我的iOS应用程序崩溃，出现以下异常：

void HandleExceptions(NSException *__strong):875 ERROR: uncaught exception: no UICollectionViewLayoutAttributes instance for -layoutAttributesForDecorationViewOfKindOfKind: ColorDecoratorView at path <NSIndexPath: 0x7d843ec0> {length = 3, path = 3 - 0}

你能告诉我"没有UICollectionViewLayoutAttributes实例for -layoutAttributesForDecorationViewOfKindOfKindKind"是什么意思吗？我应该在哪里进行故障排除？

我已经实施了这种方法：

   - (UICollectionViewLayoutAttributes *)layoutAttributesForDecorationViewOfKind:(NSString *)decorationViewKind atIndexPath:(NSIndexPath *)indexPath

但是当我旋转屏幕时，我得到以下异常：

uncaught exception: layout attributes for supplementary item at index path (<NSIndexPath: 0x79ef2c80> {length = 2, path = 1 - 0}) changed from <UICollectionViewLayoutAttributes: 0x82e76830> index path: (<NSIndexPath: 0x79ebf750> {length = 2, path = 1 - 0}); element kind: (ColorDecoratorView); frame = (72 2513; 293.333 252);  to <UICollectionViewLayoutAttributes: 0x79ef9380> index path: (<NSIndexPath: 0x79ef2c80> {length = 2, path = 1 - 0}); element kind: (ColorDecoratorView); frame = (0 825; 1024 -327);  without invalidating the layout

谢谢。

Answer 1

你在实现这个medthod吗？

- (UICollectionViewLayoutAttributes *)layoutAttributesForDecorationViewOfKind:(NSString *)decorationViewKind atIndexPath:(NSIndexPath *)indexPath

返回值为 A layout attributes object containing the information to apply to the decoration view.

我会说实现这种方法。 像这样 UICollectionViewLayoutAttributes *attrs = [UICollectionViewLayoutAttributes layoutAttributesForDecorationViewOfKind:decorationViewKind withIndexPath:indexPath]; attrs.frame = cgrectmake (x,x,x,x); return attrs;

看起来像您的单元格正在从集合视图中请求一些布局属性。NSIndexPath 似乎是 [L=3， path = 3];

获取 indexPath.row 并在 cellForRowAtIndexPath 中进一步调查。