如何在Swift中增加UILabel的行间距

Question

我有一个标签,几行文字,我想增加行之间的间距.其他人也提出了类似的问题,但解决方案并没有解决我的问题.我的标签也可能包含或不包含段落.我是新来的Swift.是否有使用故事板的解决方案？或者只通过NSAttributedString它可能的？

Answer 1

以编程方式将LineSpacing添加到您UILabel使用的以下代码段.

早期的Swift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

Answer 2

来自Interface Builder:

编程方式:

SWift 4和4.2

使用标签扩展

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
    }
}

现在调用扩展功能

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即可查看结果)

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

斯威夫特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

Answer 3

您可以控制行间距storyboard.

同样的问题.

Answer 4

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
    }

}

以及用法：

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

Answer 5

您可以使用此可重用扩展名:

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
}
}

Answer 6

斯威夫特 4 和斯威夫特 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)
    }
}

如何使用

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