小编Geo*_*oas的帖子

我遇到了一个奇怪的崩溃并试图整天修复它.我有一个自定义UICollectionViewLayout,它基本上增加了细胞的重力和碰撞.

实施效果很好!当我尝试使用以下命令删除一个单元格时会出现问题:[self.collectionView performBatchUpdates:].

它给了我以下错误:

2013-12-12 21:15:35.269 APPNAME[97890:70b] *** Assertion failure in -[UICollectionViewData validateLayoutInRect:], /SourceCache/UIKit_Sim/UIKit-2935.58/UICollectionViewData.m:357

2013-12-12 20:55:49.739 APPNAME[97438:70b] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'UICollectionView recieved layout attributes for a cell with an index path that does not exist: <NSIndexPath: 0x975d290> {length = 2, path = 0 - 4}'

我的模型处理正确,我可以看到它从中删除项目!

要删除的项的indexPaths正在对象之间正确传递.collectionView更新没有崩溃的唯一时间是我删除它上面的最后一个单元格,否则,崩溃就会发生.

这是我用来删除单元格的代码.

- (void)removeItemAtIndexPath:(NSIndexPath *)itemToRemove completion:(void (^)(void))completion
{
    UICollectionViewLayoutAttributes *attributes = [self.dynamicAnimator layoutAttributesForCellAtIndexPath:itemToRemove];

    [self.gravityBehaviour removeItem:attributes];
    [self.itemBehaviour removeItem:attributes];
    [self.collisionBehaviour removeItem:attributes];

    [self.collectionView performBatchUpdates:^{
        [self.fetchedBeacons removeObjectAtIndex:itemToRemove.row];
        [self.collectionView deleteItemsAtIndexPaths:@[itemToRemove]];
    } completion:nil];   
} …