How to get the size of a NSString

This is a different approach. Find out the minimum size of the text so that it won't wrap to more than one line. If it wraps to over one line, you can find out using the height.

You can use this code:

CGSize maximumSize = CGSizeMake(300, 9999);NSString *myString = @"This is a long string which wraps";UIFont *myFont = [UIFont fontWithName:@"Helvetica" size:14];CGSize myStringSize = [myString sizeWithFont:myFont                            constrainedToSize:maximumSize                                lineBreakMode:self.myLabel.lineBreakMode];

300 is the width of the screen with a little space for margins. You should substitute your own values for font and size, and for the lineBreakMode if you're not using IB.

Now myStringSize will contain a height which you can check against the height of something you know is only 1 line high (using the same font and size). If it's bigger, you'll need to cut the text. Note that you should add a ... to the string before you check it again (adding the ... might push it over the limit again).

Put this code in a loop to cut the text, then check again for the correct height.

Use below method.

Objective-C

- (CGSize)findHeightForText:(NSString *)text havingWidth:(CGFloat)widthValue andFont:(UIFont *)font {    CGSize size = CGSizeZero;    if (text) {        CGRect frame = [text boundingRectWithSize:CGSizeMake(widthValue, CGFLOAT_MAX) options:NSStringDrawingUsesLineFragmentOrigin attributes:@{ NSFontAttributeName:font } context:nil];        size = CGSizeMake(frame.size.width, frame.size.height + 1);    }    return size;}

Swift 3.0

func findHeight(forText text: String, havingWidth widthValue: CGFloat, andFont font: UIFont) -> CGSize {    var size = CGSizeZero    if text {        var frame = text.boundingRect(withSize: CGSize(width: widthValue, height: CGFLOAT_MAX), options: .usesLineFragmentOrigin, attributes: [NSFontAttributeName: font], context: nil)        size = CGSize(width: frame.size.width, height: frame.size.height + 1)    }    return size}

You need to use Core Graphics to measure the string, as rendered in your specified font and size. See the answers to Measuring the pixel width of a string for a walkthrough.