ios - 单元格标签文本在单元格中重叠

Question

我正在尝试将 UILabel 添加到我的 collectionViewCell。然而，一些单元格文本开始与之前单元格中的数据重叠。

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

如图所示:

我正在以编程方式实现整个 View 。该问题似乎与 collectionview 的任何元素无关，因此我认为该问题也适用于 TableView 。我不确定我是否遗漏了以下内容:

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

如果是这样，有人可以阐明它的作用吗？如果那不是问题，我真的不确定是什么原因造成的。我还使用了 NSMutableAttributedString，但这也不是问题，因为我尝试只插入一个常规字符串并得到相同的结果。

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;
}

这是我设置单元格大小的方法:

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

下面是我如何设置我的 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

移除标签并在显示单元格时重新初始化它。

- (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;
}