How to Increase Line spacing in UILabel in Swift

我有一个标签，它有几行文本，我想增加行之间的间距。其他人也有类似的问题，但是解决方案并不能解决我的问题。此外，我的标签可能包含也可能不包含段落。我是 Swift的新手。是否有使用故事板的解决方案？或者只有通过 NSAttributedString才有可能？

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最佳答案

使用以下代码片段以编程方式将 LineSpaces 添加到 UILabel。

早期的斯威夫特版本

let attributedString = NSMutableAttributedString(string: "Your text")


// *** Create instance of `NSMutableParagraphStyle`
let paragraphStyle = NSMutableParagraphStyle()


// *** set LineSpacing property in points ***
paragraphStyle.lineSpacing = 2 // Whatever line spacing you want in points


// *** Apply attribute to string ***
attributedString.addAttribute(NSParagraphStyleAttributeName, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))


// *** Set Attributed String to your label ***
label.attributedText = attributedString

Swift 4.0

let attributedString = NSMutableAttributedString(string: "Your text")


// *** Create instance of `NSMutableParagraphStyle`
let paragraphStyle = NSMutableParagraphStyle()


// *** set LineSpacing property in points ***
paragraphStyle.lineSpacing = 2 // Whatever line spacing you want in points


// *** Apply attribute to string ***
attributedString.addAttribute(NSAttributedStringKey.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))


// *** Set Attributed String to your label ***
label.attributedText = attributedString

Swift 4.2

let attributedString = NSMutableAttributedString(string: "Your text")


// *** Create instance of `NSMutableParagraphStyle`
let paragraphStyle = NSMutableParagraphStyle()


// *** set LineSpacing property in points ***
paragraphStyle.lineSpacing = 2 // Whatever line spacing you want in points


// *** Apply attribute to string ***
attributedString.addAttribute(NSAttributedString.Key.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))


// *** Set Attributed String to your label ***
label.attributedText = attributedString
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您可以在 storyboard中控制行间距。

enter image description here

同样的问题。

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Interface Builder:

enter image description here

程序设计:

SWIFT 4 & 4.2

使用标签扩展名

extension UILabel {


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)
}


// (Swift 4.2 and above) Line spacing attribute
attributedString.addAttribute(NSAttributedString.Key.paragraphStyle, value:paragraphStyle, range:NSMakeRange(0, attributedString.length))




// (Swift 4.1 and 4.0) 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 = "Set\nUILabel\nline\nspacing"


// 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

或使用标签实例(只需复制并执行此代码查看结果)

let label = UILabel()
let stringValue = "Set\nUILabel\nline\nspacing"
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

Swift 3

let label = UILabel()
let stringValue = "Set\nUILabel\nline\nspacing"
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
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迪潘的答案更新为 Swift 4

let attr = NSMutableAttributedString(string: today)
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = 2
attr.addAttribute(.paragraphStyle, value: paragraphStyle, range: NSMakeRange(0, attr.length))
label.attributedText = attr;
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您可以使用这个可重用的扩展:

extension String {


func lineSpaced(_ spacing: CGFloat) -> NSAttributedString {
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = spacing
let attributedString = NSAttributedString(string: self, attributes: [NSAttributedString.Key.paragraphStyle: paragraphStyle])
return attributedString
}
}
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//Swift 4:
func set(text:String,
inLabel:UILabel,
withLineSpacing:CGFloat,
alignment:NSTextAlignment){
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = withLineSpacing
let attrString = NSMutableAttributedString(string: text)
attrString.addAttribute(NSAttributedStringKey.paragraphStyle,
value:paragraphStyle,
range:NSMakeRange(0, attrString.length))
inLabel.attributedText = attrString
inLabel.textAlignment = alignment
}
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Swift 5.0的最新解决方案

private extension UILabel {


// MARK: - spacingValue is spacing that you need
func addInterlineSpacing(spacingValue: CGFloat = 2) {


// MARK: - Check if there's any text
guard let textString = text else { return }


// MARK: - Create "NSMutableAttributedString" with your text
let attributedString = NSMutableAttributedString(string: textString)


// MARK: - Create instance of "NSMutableParagraphStyle"
let paragraphStyle = NSMutableParagraphStyle()


// MARK: - Actually adding spacing we need to ParagraphStyle
paragraphStyle.lineSpacing = spacingValue


// MARK: - Adding ParagraphStyle to your attributed String
attributedString.addAttribute(
.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: attributedString.length
))


// MARK: - Assign string that you've modified to current attributed Text
attributedText = attributedString
}


}

用法:

let yourLabel = UILabel()
let yourText = "Hello \n world \n !"
yourLabel.text = yourText
yourLabel.addInterlineSpacing(spacingValue: 1.5)
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Swift 4 and Swift 5

extension NSAttributedString {
func withLineSpacing(_ spacing: CGFloat) -> NSAttributedString {
let attributedString = NSMutableAttributedString(attributedString: self)
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = .byTruncatingTail
paragraphStyle.lineSpacing = spacing
attributedString.addAttribute(.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: string.count))
return NSAttributedString(attributedString: attributedString)
}
}

怎么用

    let example = NSAttributedString(string: "This is Line 1 \nLine 2 \nLine 3 ").withLineSpacing(15)
testLabel.attributedText = example

Example

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extension UILabel {
var spasing:CGFloat {
get {return 0}
set {
let textAlignment = self.textAlignment
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineSpacing = newValue
let attributedString = NSAttributedString(string: self.text ?? "", attributes: [NSAttributedString.Key.paragraphStyle: paragraphStyle])
self.attributedText = attributedString
self.textAlignment = textAlignment
}
}
}




let label = UILabel()
label.text = "test"
label.spacing = 10
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In addition to using attributed strings & paragraph styles, for small adjustemnts, font descriptors can also come in handy.

For instance:

let font: UIFont = .init(
descriptor: UIFontDescriptor
.preferredFontDescriptor(withTextStyle: .body)
.withSymbolicTraits(.traitLooseLeading)!,
size: 0
)

This will create a font with a looser leading, resulting in a text with a slightly larger line height (it adds 2 points) than the default system font. traitTightLeading can also be used for the opposite effect (it reduces the leading of the font by 2 points).

我写了一篇博文比较这里的方法: https://bootstragram.com/blog/line-height-with-uikit/。

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创建标签样式

struct LabelStyle {
    

let font: UIFont
let fontMetrics: UIFontMetrics?
let lineHeight: CGFloat?
let tracking: CGFloat
        

init(font: UIFont, fontMetrics: UIFontMetrics? = nil, lineHeight: CGFloat? = nil, tracking: CGFloat = 0) {
self.font = font
self.fontMetrics = fontMetrics
self.lineHeight = lineHeight
self.tracking = tracking
}
        

func attributes(for alignment: NSTextAlignment, lineBreakMode: NSLineBreakMode) -> [NSAttributedString.Key: Any] {
            

let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.alignment = alignment
paragraphStyle.lineBreakMode = lineBreakMode
            

var baselineOffset: CGFloat = .zero
            

if let lineHeight = lineHeight {
let lineHeightMultiple = lineHeight / font.lineHeight
paragraphStyle.lineHeightMultiple = lineHeightMultiple
                

baselineOffset = 1 / lineHeightMultiple
                

let scaledLineHeight: CGFloat = fontMetrics?.scaledValue(for: lineHeight) ?? lineHeight
paragraphStyle.minimumLineHeight = scaledLineHeight
paragraphStyle.maximumLineHeight = scaledLineHeight
}
            

return [
NSAttributedString.Key.paragraphStyle: paragraphStyle,
NSAttributedString.Key.kern: tracking,
NSAttributedString.Key.baselineOffset: baselineOffset,
NSAttributedString.Key.font: font
]
}
}

Create custom Label class and use our style

public class Label: UILabel {
  

var style: LabelStyle? { nil }
  

public override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
super.traitCollectionDidChange(previousTraitCollection)
    

if previousTraitCollection?.preferredContentSizeCategory != traitCollection.preferredContentSizeCategory {
updateText()
}
}
  

convenience init(text: String?, textColor: UIColor) {
self.init()
self.text = text
self.textColor = textColor
}
  

override init(frame: CGRect) {
super.init(frame: frame)
commonInit()
}
  

required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
commonInit()
updateText()
}
  

private func commonInit() {
font = style?.font
adjustsFontForContentSizeCategory = true
}
  

private func updateText() {
text = super.text
}
  

public override var text: String? {
get {
guard style?.attributes != nil else {
return super.text
}
      

return attributedText?.string
}
set {
guard let style = style else {
super.text = newValue
return
}
      

guard let newText = newValue else {
attributedText = nil
super.text = nil
return
}
      

let attributes = style.attributes(for: textAlignment, lineBreakMode: lineBreakMode)
attributedText = NSAttributedString(string: newText, attributes: attributes)
}
}
}

创建具体的标签

public final class TitleLabel {


override var style: LabelStyle? {
LabelStyle(
font: UIFont.Title(),
lineHeight: 26.21,
tracking: 0.14
)
}
}

然后利用它

@IBOutlet weak var titleLabel: TitleLabel!
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这个解决方案对 Swift 5很有效 this is reference to answer of https://stackoverflow.com/a/62116213/13171606

我做了一些改变“ NSMutableAttributedString”和包括完整的例子，我认为它将帮助你所有

注意: 如果发现任何错误，请调整颜色和字体样式。

分机

extension NSAttributedString {
func withLineSpacing(_ spacing: CGFloat) -> NSMutableAttributedString {
let attributedString = NSMutableAttributedString(attributedString: self)
let paragraphStyle = NSMutableParagraphStyle()
paragraphStyle.lineBreakMode = .byTruncatingTail
paragraphStyle.lineSpacing = spacing
attributedString.addAttribute(.paragraphStyle,
value: paragraphStyle,
range: NSRange(location: 0, length: string.count))
return NSMutableAttributedString(attributedString: attributedString)
}
}

Implementation Example

let myAttributedText = NSMutableAttributedString(string: "Please enter the required details to change your AAAAAAAAA AAAAA AAAAA. Maximum AAAAA can be AAA AA AAA AA.\n\nNote: If you do not have a AAAAA AAAA then please AAAAAAA us at 111-111-111 or send us an email AAAA AAAA AAA AAAAAAAAAA AAAAA address at xxxxxxxxxxxxxxxxxxxxxxxxxxxx.", attributes: [
.font: UIFont.systemFont(ofSize: 14),
.foregroundColor: UIColor.gray,
.kern: 0.0]).withLineSpacing(8)
myAttributedText.addAttributes([
.font: UIFont.systemFont(ofSize: 14),
.foregroundColor: UIColor.blue],
range: NSRange(location: 174, length: 11))
myAttributedText.addAttributes([
.font: UIFont.systemFont(ofSize: 14),
.foregroundColor: UIColor.blue],
range: NSRange(location: 248, length: 28))

UILable

let myLabel: UILabel = {
let label = UILabel()
label.textAlignment = .left
label.numberOfLines = 0
label.attributedText = myAttributedText //Here is your Attributed String
return label
}()

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