集合视图与单元格重叠

Question

我的目标是在我的视图的页脚有一个集合视图。单元格中充满了照片库中的照片。我不知道为什么，但细胞是相互重叠的。有人知道为什么吗？以下是来自视图控制器的代码：

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
    return 1;
}
- (NSInteger)collectionView:(UICollectionView *)collectionView
     numberOfItemsInSection:(NSInteger)section
{
    return [self.fotoArray count];
}
- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
                  cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier = @"foto_cell";
    FotoCell *cell = [self.collectionView
                        dequeueReusableCellWithReuseIdentifier:cellIdentifier
                        forIndexPath:indexPath];
    Foto *currFoto = [self.fotoArray objectAtIndex:indexPath.row];
    // Set the selectedFotoID 
    [CoreDataManager sharedInstance].selectedFotoId = ((Foto*)[self.fotoArray objectAtIndex:indexPath.row]).objectID;
    NSURL *u = [NSURL URLWithString:currFoto.f_path];
    [self findImage:u in: cell];

    return cell;
}
// Get Photo from Asset Library
-(void)findImage:(NSURL*)u in: (FotoCell*) cell
{
    __block FotoCell *blockCell = cell;
    //
    ALAssetsLibraryAssetForURLResultBlock resultblock = ^(ALAsset *myasset)
    {
        ALAssetRepresentation *rep = [myasset defaultRepresentation];
        CGImageRef iref = [rep fullResolutionImage];
        if (iref) {
            UIImage *largeimage = [UIImage imageWithCGImage:iref];
            //[largeimage retain];
            UIImage *thumbnail = [UIImage imageWithCGImage:iref scale:0.15 orientation:UIImageOrientationUp];
            [blockCell.fotoThumb setImage:thumbnail];
        }
    };
    //
    ALAssetsLibraryAccessFailureBlock failureblock  = ^(NSError *myerror)
    {
        NSLog(@"cant get image - %@",[myerror localizedDescription]);
    };

        NSURL *asseturl = u;
        ALAssetsLibrary* assetslibrary = [[[ALAssetsLibrary alloc] init] autorelease];
        [assetslibrary assetForURL:asseturl
                       resultBlock:resultblock
                      failureBlock:failureblock];
}

这是我的 Cell.m 类中的代码：

@implementation FotoCell
- (id)initWithFrame:(CGRect)frame
{
    self = [super initWithFrame:frame];
    if (self) {
        // Initialization code
    }
    return self;
}

- (void)dealloc {
    [_fotoThumb release];
    [super dealloc];
}
@end

Answer 1

我不清楚你的代码。但我以前遇到过这个问题。原因是您在cellForItemAtIndexPath中添加了可见视图（如图像UILabel,...）：

当集合视图序列时，滚动时所有单元格视图都重叠在一起。

您可以尝试在单元格中初始化和图像视图，然后在单元格中设置图像名称

Answer 2

您必须设置UICollectionViewFlowLayout实例的itemSize。