ios - 根据标签大小调整 UICollectionViewCell 的大小

Question

我有一个 UICollectionView，它将包含带有不同大小标签的单元格。我正在尝试根据标签的大小调整单元格的大小。但是，我创建单元格的 sizeForItemAtIndexPath 似乎在我设置标签的 cellForItemAtIndexPath 之前被调用。我可以在这里做什么？

- (void)getLabelSize:(UILabel *)label {
    float widthIs = [label.text boundingRectWithSize:label.frame.size options:NSStringDrawingUsesLineFragmentOrigin attributes:@{ NSFontAttributeName:label.font } context:nil].size.width;

    width = widthIs;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    // Configure the cell
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:reuseIdentifier forIndexPath:indexPath];
    UILabel *label = (UILabel *)[cell viewWithTag:1000];
    label.text = @"This is pretty long";
    [label sizeToFit];
    [self getLabelSize:label];
    NSLog([NSString stringWithFormat:@"%f", width]);
    cell.backgroundColor = [UIColor whiteColor];

    return cell;   
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout*)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return CGSizeMake(width, 50);
}

Answer 1

在 swift 中，我计算了标签的文本大小并根据它更新了单元格大小:

func collectionView(_ collectionView: UICollectionView,
                        layout collectionViewLayout: UICollectionViewLayout,
                        sizeForItemAt indexPath: IndexPath) -> CGSize {


        let size: CGSize = keywordArray[indexPath.row].size(attributes: [NSFontAttributeName: UIFont.systemFont(ofSize: 14.0)])
        return CGSize(width: size.width + 45.0, height: keywordsCollectionView.bounds.size.height)
    }

因为我有一个额外的按钮和填充，所以我计算出额外的值是 45.0