UITableViewCell: get the exact width of UILabel in cell

Question

I am having the problem when getting the correct width of the label in custom cell. This is my cell in storyboard:

When the table is created, I understand that when cellForRowAtIndexPath is called, the cell is just created and not added to UITableView yet, so the width of the label is 304px. This causes the result like this:

After scrolling, the cell has been added to the UITableView so it shows correctly, with the width of the label is 164px.

Is there any way to know the exact width of cell/label before it is added to UITableView?

The constraints on the label: Leading, Trailing, Top and Height

Below is source code:

func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
    let cell: ArticleCell = tableView.dequeueReusableCellWithIdentifier("articleCell", forIndexPath: indexPath) as! ArticleCell
    let item = array.objectAtIndex(indexPath.row) as! Article
    cell.showDataForArticle(item, dateFormatter: dateFormatter)
    return cell
}

func showDataForArticle(article: Article, dateFormatter: NSDateFormatter) {
    self.titleLbl.text = article.articleTitle
    titleHeightConstraint.constant = titleLbl.requiredHeight() <--- where problem happens

    self.thumbnailImgView.imageLink(article.articleThumbnailLink!)
    self.authorLbl.text = article.articleCreator
    self.dateLbl.text = dateFormatter.stringFromDate(article.articlePubDate!)
}


extension UILabel {
func requiredHeight() -> CGFloat {
    let frame = CGRectMake(0, 0, self.frame.size.width, CGFloat.max)
    let label: UILabel = UILabel(frame: frame)
    label.numberOfLines = 0
    label.lineBreakMode = .ByWordWrapping
    label.font = self.font
    label.text = self.text
    label.sizeToFit()

    return label.frame.size.height
}

try subclassing the tableview cell and findout the bounds in layoutsubviews method or initWithStyle method. — Teja Nandamuri, Mar 27 '16 at 16:34
@ryantxr the height constraint for the "Header" label, I want to expand it according to text. But initially, the width is wrong, after the cell is added to tableview, the width is right. — haisergeant, Mar 27 '16 at 17:34
Why you are calculating the height required for your label as you are using auto layouts? Just simply set the constraint to the top label as, LeadingSpace to ImageView TrailingSpace to cell with StandardSpacing or some fixed pts, set Bottom space to bottom label with StandardSpacing. Thats it. — Bharat Modi, Mar 28 '16 at 05:19
Because I would like to have that UILabel extend automatically with the text inside. You can take a look on the third screenshot, which shows the correct result after scrolling. I just edit to add the fourth screenshot about constraints on UILabel — haisergeant, Mar 28 '16 at 08:54
But you can manage this with the auto layouts only, there is no need to manually calculate the height required for the label. — Bharat Modi, Mar 28 '16 at 09:01
hmm, can you show me some sample code? UILabel can extend the height based on its content. Special thanks. — haisergeant, Mar 28 '16 at 09:26

score 0 · Answer 1 · edited Mar 28 '16 at 10:07

0

Try calling titleLbl.requiredHeight() in func tableView(_ tableView: UITableView, willDisplayCell cell: UITableViewCell, forRowAtIndexPath indexPath: NSIndexPath) method

edited Mar 28 '16 at 10:07

seenukarthi

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answered Mar 27 '16 at 20:42

Asad Khan

365
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score 0 · Answer 2 · answered Mar 27 '16 at 23:50

0

As far as trying to get the width of the label have you tried something alone the lines of

self.YourLabelName.bounds.width

answered Mar 27 '16 at 23:50

Dallas

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score 0 · Answer 3 · edited May 23 '17 at 12:07

You can have a label that would adjust its height based on the text it has to show using auto layouts.

1. For this to work you should not set static height for your cell, just add the below two delegates,

    -(CGFloat)tableView:(UITableView *)tableView estimatedHeightForRowAtIndexPath:(NSIndexPath *)indexPath {
        return 44;
    }

    -(CGFloat)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath {
       return UITableViewAutomaticDimension;
    }

2. You should set top to bottom constraint for your cell, In your case your header label should have TopSpace to Cell, LeadingSpace to ImageView, TrailingSpace to Cell (with standard spacing) and BottomSpace to AuthorLabel(with standard spacing).

3. The label you want with dynamic height as per text should have set the number of lines to 0 and LineBreakMode to Word Wrap.

Thats it, also find this links similar to your case,

Dynamic UITableViewCell content does not expand cell

Dynamically increase height of UILabel & TableView Cell?

UITableViewCell: get the exact width of UILabel in cell

3 Answers3