UILabel attributed text can't have multiple lines if you change baseline offset attribute

Question

I want to change brackets's baseline offset in a words, like "[推]blablabla".

NSRange range = [text rangeOfString:@"[推]"];
if (range.location == 0) {
    [text addAttribute:NSBaselineOffsetAttributeName value:@(0.5) range:NSMakeRange(0, 1)];
    [text addAttribute:NSBaselineOffsetAttributeName value:@(0.5) range:NSMakeRange(range.length-1, 1)];
}

but the second line of the label disappears and gets truncated. Anyone have an idea?

I meet the same issue, looks like bug to me. – Alen Liang Jul 09 '17 at 10:30 — Alen Liang, Jul 09 '17 at 10:30

score 4 · Answer 1 · answered May 06 '16 at 10:14

4

Please use lineBreakMode and numberOfLines Also to call sizeToFit, like this:

label.lineBreakMode = UILineBreakModeWordWrap;
label.numberOfLines = 0;
[label sizeToFit];

The height will be automatically computed.

Thanks

answered May 06 '16 at 10:14

Vijay Kachhadiya

366
2
11

I use autolayout, sizeToFit is useless. I already set lineBreakMode = NSLineBreakByTruncatingTail and numberOfLines = 2. – Monqi May 06 '16 at 10:41

score 1 · Answer 2 · answered Jul 04 '17 at 03:51

1

I've did some quick test, and it seems that if you add a whitespace at the first of your string, it will work as expected

// make sure your text looks like @" [推]your content"
if (range.location == 1) {
    [text addAttribute:NSBaselineOffsetAttributeName value:@(0.5) range:NSMakeRange(1, 1)];
    [text addAttribute:NSBaselineOffsetAttributeName value:@(0.5) range:NSMakeRange(range.length, 1)];
}

answered Jul 04 '17 at 03:51

xi.lin

3,326
2
31
57

I test and it don't work. can you explain your code a little more. – Alen Liang Jul 09 '17 at 10:29
@AlenLiang In my experiment, the setting of `NSBaselineOffsetAttributeName` on different characters will effect the truncation. Try different combination of range index will make it correct. Are you sure your text is like `@" [推]your content"`, especially have a space in the first? – xi.lin Jul 10 '17 at 07:15
Try different combination of range index will make it correct. sounds quite tricky for me, I don't use @" [推]your content", just add a whitespace at the beginning of my string. Still it looks like bug. – Alen Liang Jul 11 '17 at 15:13
@AlenLiang Yeah. I think we can open a radar – xi.lin Jul 12 '17 at 02:03
I happen to test this bug, and now it works whatever your string is. in iOS 11. – Alen Liang Mar 21 '18 at 06:37

score 0 · Answer 3 · answered May 06 '16 at 10:20

If you using storyboard see the below image, select the Label, then see the Lines is set 0 and Line Breaks set Word Wrap thats solve.

or if you use code,

Objective C:

LabelName.lineBreakMode = UILineBreakModeWordWrap;
LabelName.numberOfLines = 0;

Swift:

LabelName.lineBreakMode = .ByWordWrapping
LabelName.numberOfLines = 0

hope its helpful

score 0 · Answer 4 · edited May 23 '17 at 12:10

Did you try using NSMutableParagraphStyle to set lineBreakMode as attribute?

NSMutableParagraphStyle *paragrahStyle = [[NSMutableParagraphStyle alloc] init];
[paragrahStyle setLineBreakMode:NSLineBreakByTruncatingTail];

[attributedText addAttribute:NSParagraphStyleAttributeName value:paragrahStyle range:NSMakeRange(0, [attributedText length])];

like proposed here: UILabel attributedText with multiple line break modes

UILabel attributed text can't have multiple lines if you change baseline offset attribute

4 Answers4