在ios6中有另一个答案，那就是在标签上设置attributedText，使用NSAttributedString和适当的段落样式。关于NSAttributedString的行高，请参阅堆栈溢出答案:

NSAttributedString行高，对吗?

在Xcode 6中，你可以在storyboard中这样做:

另一个答案……如果你通过编程的方式传递字符串，你需要传递一个带属性的字符串，而不是一个普通的字符串，并改变它的风格。

NSMutableAttributedString * attrString = [[NSMutableAttributedString alloc] initWithString:@"Your \nregular \nstring"];
NSMutableParagraphStyle *style = [[NSMutableParagraphStyle alloc] init];
[style setLineSpacing:4];
[attrString addAttribute:NSParagraphStyleAttributeName
                   value:style
                   range:NSMakeRange(0, attrString.length)];
_label.attributedText = attrString;

这应该会有帮助。然后你可以将你的标签分配给故事板中的这个自定义类，并直接在属性中使用它的参数:

open class SpacingLabel : UILabel {

    @IBInspectable open var lineHeight:CGFloat = 1 {
        didSet {
            let paragraphStyle = NSMutableParagraphStyle()
            paragraphStyle.lineSpacing = 1.0
            paragraphStyle.lineHeightMultiple = self.lineHeight
            paragraphStyle.alignment = self.textAlignment

            let attrString = NSMutableAttributedString(string: self.text!)
            attrString.addAttribute(NSAttributedStringKey.font, value: self.font, range: NSMakeRange(0, attrString.length))
            attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attrString.length))
            self.attributedText = attrString
        }
    } 
}

从ios6开始，你可以为UILabel设置带属性字符串。检查以下内容:

NSMutableAttributedString *attributedString = [[NSMutableAttributedString alloc] initWithString:label.text];
NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineSpacing = spacing;
[attributedString addAttribute:NSParagraphStyleAttributeName value:paragraphStyle range:NSMakeRange(0, label.text.length)];

label.attributedText = attributedString;

这段代码适用于我(ios 7和ios 8肯定是如此)。

_label.numberOfLines=2;
_label.textColor=[UIColor whiteColor];

NSMutableParagraphStyle *paragraphStyle = [[NSMutableParagraphStyle alloc] init];
paragraphStyle.lineHeightMultiple=0.5;
paragraphStyle.alignment = NSTextAlignmentCenter;
paragraphStyle.lineSpacing = 1.0;

NSDictionary *nameAttributes=@{
                               NSParagraphStyleAttributeName : paragraphStyle,
                               NSBaselineOffsetAttributeName:@2.0
                               };


NSAttributedString *string=[[NSAttributedString alloc] initWithString:@"22m\nago" attributes:nameAttributes];
_label.attributedText=string;