iOS 6 multiline label line spacing - ios

Question

There is a problem with line spacing in UILabel, I am using custom font and when I use smilies there is no space between two lines. which obviously looks not so good. So I used this code for line spacing but app crashes giving the error
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'NSAttributedString invalid for autoresizing, it must have a single spanning paragraph style (or none) with a non-wrapping lineBreakMode.'
if ([cell.label2 respondsToSelector:#selector(setAttributedText:)])
{
UIFont *font =btMyriadProRegularWithSize14Pt;
NSMutableParagraphStyle *paragraphStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy];
[paragraphStyle setLineSpacing: 22];
NSDictionary *attributes = #{ NSFontAttributeName: font, NSParagraphStyleAttributeName: paragraphStyle };
NSAttributedString *attributedString = [[NSAttributedString alloc] initWithString:chatMessage.msgString attributes:attributes];
[cell.label2 setAttributedText: attributedString];
}
else
{
NSString * msg = [NSString stringWithFormat:#"%#: %#",chatMessage.from,chatMessage.msgString];
cell.label2.text = msg;
}

Answer 1

try this
[cell.label2 setAdjustsFontSizeToFitWidth:NO];
maybe even only for iOS6
if (floor(NSFoundationVersionNumber) <= NSFoundationVersionNumber_iOS_6_1) { //*
[cell.label2 setAdjustsFontSizeToFitWidth:NO];
}
detect iOS 6 as decribed here: https://developer.apple.com/library/ios/documentation/userexperience/conceptual/transitionguide/SupportingEarlieriOS.html

Answer 2

Set up Attributable String
NSMutableParagraphStyle *paragraph = [[NSMutableParagraphStyle alloc] init];
[paragraph setLineBreakMode:NSLineBreakByWordWrapping];
[paragraph setLineBreakMode:NSLineBreakByTruncatingTail];
self.attrText = [[NSMutableAttributedString alloc] initWithString:text];
[self.attrText addAttribute:NSParagraphStyleAttributeName value:paragraph range:NSMakeRange(0, text.length)];
self.Text = text;