UICollectionView收到了一个索引路径不存在的单元格的布局属性

Question

我使用UICollection视图来显示网格布局中的项目.

对于数据源,我使用5*5维数组.

而且我在section中为numberOfItems返回5,为numberOfSections返回5.

然后我的应用程序也崩溃了以下错误:

'UICollectionView收到了一个不存在索引路径的单元格的布局属性:{length = 2,path = 0 - 5}'

//////===viewcontroller.m==///////
- (void)viewDidLoad {
    self.theData = @[@[@"1",@"2",@"3",@"4",@"5"], @[@"6",@"7",@"8",@"9",@"10"],@[@"11",@"12",@"13",@"14",@"15"],@[@"16",@"17",@"18",@"19",@"20"],@[@"21",@"22",@"23",@"24",@"25"]];
    MultpleLineLayout *layout = [[MultpleLineLayout alloc] init];
    self.collectionView.collectionViewLayout = layout;
    self.collectionView.showsHorizontalScrollIndicator = NO;
    self.collectionView.showsVerticalScrollIndicator = NO;
    layout.scrollDirection = UICollectionViewScrollDirectionHorizontal;
    self.view.backgroundColor = [UIColor blackColor];
    [self.collectionView registerClass:[DataCell class] forCellWithReuseIdentifier:@"DataCell"];
    [self.collectionView reloadData];
}


- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section
{
    return 5;

}

- (NSInteger)numberOfSectionsInCollectionView: (UICollectionView *)collectionView {
    return 5;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView  cellForItemAtIndexPath:(NSIndexPath *)indexPath {

    DataCell *cell = [collectionView  dequeueReusableCellWithReuseIdentifier:@"DataCell" forIndexPath:indexPath];
    cell.label.text = self.theData[indexPath.section ][indexPath.row];
    return cell;
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
   // UICollectionViewCell *item = [collectionView cellForItemAtIndexPath:indexPath];
    NSLog(@"%@",indexPath);

}
///////////////////////

有人能解决这个问题吗？提前致谢.

Answer 1

MultipleLineLayout最初是为无限滚动编写的,因此该实现存在问题供您使用.看起来应该是这样的,

-(NSArray*)layoutAttributesForElementsInRect:(CGRect)rect {

    NSMutableArray* attributes = [NSMutableArray array];
    for(NSInteger i=0 ; i < self.collectionView.numberOfSections; i++) {
        for (NSInteger j=0 ; j < [self.collectionView numberOfItemsInSection:i]; j++) {
            NSIndexPath* indexPath = [NSIndexPath indexPathForItem:j inSection:i];
            [attributes addObject:[self layoutAttributesForItemAtIndexPath:indexPath]];
        }
    }
    return attributes;
}

Answer 2

以防其他人在Google上发现这个问题 - 我收到了一个非常有趣的索引路径相同的错误:

'NSInternalInconsistencyException',原因:'UICollectionView接收的索引路径不存在的单元格的布局属性:{length = 2,path = 0 - 0}'

我只是忘了将集合视图的数据源和委托连接到Interface Builder中的视图控制器.D'哦!