单元格标签文本在单元格中重叠

Question

我正在尝试向UILabel添加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上（iphone 5），但不在模拟器上（2013 macbook air）。

如下所示：

我正在以编程方式实现整个视图。该问题似乎与collectionview的任何元素无关，因此我认为问题也适用于表视图。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，有人可以说清楚它的作用吗？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;
}

以下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collectionView的方式：

- (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;
}

Answer 2

您只需勾选＆＃34;清除图形背景＆＃34;故事板中标签的属性。

Answer 3

单元格已经包含元素，您还可以通过编程方式创建（添加）标签。

你要做的是：

1.删除UIStoryBoard中UITableViewCell内的UILabel＆amp;＆amp;以编程方式创建。

   - (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;
    }

OR

2.在故事板中添加UILabel并使用它的参考＆amp;＆amp;不要在代码中创建只引用（指向）。

使用标记属性指向元素。

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

    UILabel *cellLabel = (UILabel*)[cell ViewWithTag:25];
        [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]; Don't add this again

        return cell;
    }