UILabel shows fewer lines then expected with multiple lines mode - ios

Question

I'd like my UILabel to show my data in multiple lines, and the data is fetch from txt file.
I've searched online for this question, and all the answers show that I just need to set lineBreakMode to NSLineBreakByWordWrapping and numberOfLines = 0. However, the problem is that, even though I added these settings, the labels shows fewer lines than expected (my data has 4 lines, however the label only shows 2 lines). Here's my code:
-(void)updateFileContentLabel:(NSString*)content{
self.fileContentLabel.text = content;
self.fileContentLabel.lineBreakMode = NSLineBreakByWordWrapping;
self.fileContentLabel.font = [UIFont systemFontOfSize:17.0f];
self.fileContentLabel.numberOfLines = 0;
[self.fileContentLabel sizeToFit];
NSLog(#"file Label: %#",self.fileContentLabel.text);
}
As you see, I have a NSLog to show the content of label's text. And the text of label in NSLog is correct (4 lines). However on the phone or simulator, it only shows 2 lines instead of 4. Does anyone know where is the problem? Thanks!

Answer 1

Probably your UILabel is just not big enough. Solutions:
1.Increase a label size.
2.Add following code to allow UILabel to decrease the font size if needed.
self.fileContentLabel.minimumScaleFactor = 0.5;

Answer 2

I was only able to replicate your problem when I was using auto layout and didn't have constraints set up for fileContentLabel, so check that out.

Answer 3

Use the following method to calculate the height of text and set the frame of label accordingly.
- (CGSize)boundingSizeWithFont:(UIFont *)font constrainedToSize:(CGSize)size lineBreakMode:(NSLineBreakMode)lineBreakMode
{
CGSize stringSize;
if ([self respondsToSelector:#selector(boundingRectWithSize:options:attributes:context:)]) {
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineBreakMode = lineBreakMode;
NSDictionary * stringAttributes = #{ NSFontAttributeName: font, paragraphStyle: NSParagraphStyleAttributeName};
stringSize = [self boundingRectWithSize:size
options:NSStringDrawingUsesLineFragmentOrigin
attributes:stringAttributes context:nil].size;
stringSize = CGSizeMake(ceil(stringSize.width), ceil(stringSize.height) + 2);
} else {
stringSize = [self sizeWithFont:font constrainedToSize:size lineBreakMode:lineBreakMode];
}
return stringSize;
}