Swift 4标签扩展。在传入函数之前创建NSMutableAttributedString，以防有属性文本需要额外的属性。

extension UILabel {

    func setLineHeightMultiple(to height: CGFloat, withAttributedText attributedText: NSMutableAttributedString) {

        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = 1.0
        paragraphStyle.lineHeightMultiple = height
        paragraphStyle.alignment = textAlignment

        attributedText.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSRange(location: 0, length: attributedText.length - 1))

        self.attributedText = attributedText
    }
}

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;

从接口生成器(Storyboard/XIB):

编程:

斯威夫特4

使用标签扩展

extension UILabel {

    // Pass value for any one of both parameters and see result
    func setLineSpacing(lineSpacing: CGFloat = 0.0, lineHeightMultiple: CGFloat = 0.0) {

        guard let labelText = self.text else { return }

        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = lineSpacing
        paragraphStyle.lineHeightMultiple = lineHeightMultiple

        let attributedString:NSMutableAttributedString
        if let labelattributedText = self.attributedText {
            attributedString = NSMutableAttributedString(attributedString: labelattributedText)
        } else {
            attributedString = NSMutableAttributedString(string: labelText)
        }

        // Line spacing attribute
        attributedString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))

        self.attributedText = attributedString
    }
}

现在调用扩展函数

let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"

// Pass value for any one argument - lineSpacing or lineHeightMultiple
label.setLineSpacing(lineSpacing: 2.0) .  // try values 1.0 to 5.0

// or try lineHeightMultiple
//label.setLineSpacing(lineHeightMultiple = 2.0) // try values 0.5 to 2.0

或者使用标签实例(只要复制并执行这段代码就可以看到结果)

let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40

// Line spacing attribute
attrString.addAttribute(NSAttributedStringKey.paragraphStyle, value: style, range: NSRange(location: 0, length: stringValue.characters.count))

// Character spacing attribute
attrString.addAttribute(NSAttributedStringKey.kern, value: 2, range: NSMakeRange(0, attrString.length))

label.attributedText = attrString

斯威夫特3

let label = UILabel()
let stringValue = "How to\ncontrol\nthe\nline spacing\nin UILabel"
let attrString = NSMutableAttributedString(string: stringValue)
var style = NSMutableParagraphStyle()
style.lineSpacing = 24 // change line spacing between paragraph like 36 or 48
style.minimumLineHeight = 20 // change line spacing between each line like 30 or 40
attrString.addAttribute(NSParagraphStyleAttributeName, value: style, range: NSRange(location: 0, length: stringValue.characters.count))
label.attributedText = attrString

这是我在swift中的解决方案。子类应该同时适用于attributedText和text属性以及characterSpacing + lineSpacing。如果设置了新字符串或attributedString，则保留空格。

open class UHBCustomLabel : UILabel {
    @IBInspectable open var characterSpacing:CGFloat = 1 {
        didSet {
            updateWithSpacing()
        }

    }
    @IBInspectable open var lines_spacing:CGFloat = -1 {
        didSet {
            updateWithSpacing()
        }

    }
    open override var text: String? {
        set {
            super.text = newValue
            updateWithSpacing()
        }
        get {
            return super.text
        }
    }
    open override var attributedText: NSAttributedString? {
        set {
            super.attributedText = newValue
            updateWithSpacing() 
        }
        get {
            return super.attributedText
        }
    }
    func updateWithSpacing() {
        let attributedString = self.attributedText == nil ? NSMutableAttributedString(string: self.text ?? "") : NSMutableAttributedString(attributedString: attributedText!)
        attributedString.addAttribute(NSKernAttributeName, value: self.characterSpacing, range: NSRange(location: 0, length: attributedString.length))
        if lines_spacing >= 0 {
            let paragraphStyle = NSMutableParagraphStyle()
            paragraphStyle.lineSpacing = lines_spacing
            paragraphStyle.alignment = textAlignment
            attributedString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))
        }
        super.attributedText = attributedString
    }
}

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;

我做了这个简单的扩展，非常适合我:

extension UILabel {
    func setLineHeight(lineHeight: CGFloat) {
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = 1.0
        paragraphStyle.lineHeightMultiple = lineHeight
        paragraphStyle.alignment = self.textAlignment

        let attrString = NSMutableAttributedString()
        if (self.attributedText != nil) {
            attrString.append( self.attributedText!)
        } else {
            attrString.append( 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
    }
}

复制到一个文件中，这样你就可以像这样使用它了

myLabel.setLineHeight(0.7)