单元格标签文本在单元格中重叠

Question

我正在尝试添加一个UILabel给我的collectionViewCell.但是,在一些单元格文本开始与之前的单元格数据重叠之后.

更新:这似乎只发生在我的手机(iphone 5)上,但不在模拟器上(2013 macbook air).

如下所示:

我以编程方式实现整个视图.问题似乎与任何元素没有关系collectionview,所以我认为问题也适用于表格视图.我不确定我是否遗漏了以下内容:

if(cell == nil) {// do something }

如果是这样的话,有人可以解释一下它的作用吗？如果这不是问题,我真的不确定是什么导致了这个问题.我也在使用NSMutableAttributedString,但这不是问题,因为我试图插入一个常规字符串并获得相同的结果.

我的代码:

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath];
    TTSong *tempSong = [songArray objectAtIndex:indexPath.row];

UILabel *cellLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 110, 150, 40)];
    [cellLabel setTextColor:[UIColor whiteColor]];
    [cellLabel setBackgroundColor:[UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.8]];
    [cellLabel setFont:[UIFont fontWithName: @"HelveticaNeue-Light" size: 12.0f]];
    [cellLabel setNumberOfLines:2];
    NSString * labelString = [[tempSong.artist stringByAppendingString:@"\n"] stringByAppendingString:tempSong.title];
    NSMutableAttributedString * attributedString = [[NSMutableAttributedString alloc] initWithString:labelString];
    NSRange boldedRange = NSMakeRange(0, tempSong.artist.length);
    [attributedString addAttribute: NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue" size:14.0f] range:boldedRange];
    [cellLabel setAttributedText:attributedString];
    [cell addSubview:cellLabel];

    return cell;
}

这是我如何设置单元格的大小:

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(150, 150);
}

以下是我设置我的方法collectionView:

- (void)viewDidLoad
{
    songArray = [[NSMutableArray alloc] init];

    UICollectionViewFlowLayout *layout=[[UICollectionViewFlowLayout alloc] init];
    _collectionView=[[UICollectionView alloc] initWithFrame:self.view.frame collectionViewLayout:layout];
    [_collectionView setDataSource:self];
    [_collectionView setDelegate:self];

    [_collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"cellIdentifier"];
    [_collectionView setBackgroundColor:[UIColor blackColor]];

    [self.view addSubview:_collectionView];
[super viewDidLoad];
}

Answer 1

删除标签并在显示单元格时重新初始化.

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"cellIdentifier" forIndexPath:indexPath];
    TTSong *tempSong = [songArray objectAtIndex:indexPath.row];

    for (UILabel *lbl in cell.contentView.subviews)
    {
        if ([lbl isKindOfClass:[UILabel class]])
        {
            [lbl removeFromSuperview];
        }
    }

    UILabel *cellLabel = [[UILabel alloc] initWithFrame:CGRectMake(0, 110, 150, 40)];
    [cellLabel setTextColor:[UIColor whiteColor]];
    [cellLabel setBackgroundColor:[UIColor colorWithRed:0.0 green:0.0 blue:0.0 alpha:0.8]];
    [cellLabel setFont:[UIFont fontWithName: @"HelveticaNeue-Light" size: 12.0f]];
    [cellLabel setNumberOfLines:2];
    NSString * labelString = [[tempSong.artist stringByAppendingString:@"\n"] stringByAppendingString:tempSong.title];
    NSMutableAttributedString * attributedString = [[NSMutableAttributedString alloc] initWithString:labelString];
    NSRange boldedRange = NSMakeRange(0, tempSong.artist.length);
    [attributedString addAttribute: NSFontAttributeName value:[UIFont fontWithName:@"HelveticaNeue" size:14.0f] range:boldedRange];
    [cellLabel setAttributedText:attributedString];
    [cell addSubview:cellLabel];

    return cell;
}