Question

如何在Swift中强调UILabel？我搜索了Objective-C但却无法让它们在Swift中工作。

Answer 1

执行此操作

示例：

let underlineAttribute = [NSUnderlineStyleAttributeName: NSUnderlineStyle.StyleSingle.rawValue]
let underlineAttributedString = NSAttributedString(string: "StringWithUnderLine", attributes: underlineAttribute)
myLabel.attributedText = underlineAttributedString

修改

要为一个UILabel的所有文本提供相同的属性，我建议您继承UILabel并覆盖文本，如下所示：

Swift 4.2

class UnderlinedLabel: UILabel { override var text: String? { didSet { guard let text = text else { return } let textRange = NSMakeRange(0, text.count) let attributedText = NSMutableAttributedString(string: text) attributedText.addAttribute(NSAttributedString.Key.underlineStyle , value: NSUnderlineStyle.single.rawValue, range: textRange) // Add other attributes if needed self.attributedText = attributedText } } }

Swift 3.0

class UnderlinedLabel: UILabel { override var text: String? { didSet { guard let text = text else { return } let textRange = NSMakeRange(0, text.characters.count) let attributedText = NSMutableAttributedString(string: text) attributedText.addAttribute(NSUnderlineStyleAttributeName , value: NSUnderlineStyle.styleSingle.rawValue, range: textRange) // Add other attributes if needed self.attributedText = attributedText } } }

你把你的文字写成：

@IBOutlet weak var label: UnderlinedLabel! override func viewDidLoad() { super.viewDidLoad() label.text = "StringWithUnderLine" }

OLD：

Swift（2.0到2.3）：

class UnderlinedLabel: UILabel { override var text: String? { didSet { guard let text = text else { return } let textRange = NSMakeRange(0, text.characters.count) let attributedText = NSMutableAttributedString(string: text) attributedText.addAttribute(NSUnderlineStyleAttributeName, value:NSUnderlineStyle.StyleSingle.rawValue, range: textRange) // Add other attributes if needed self.attributedText = attributedText } } }

Swift 1.2：

class UnderlinedLabel: UILabel { override var text: String! { didSet { let textRange = NSMakeRange(0, count(text)) let attributedText = NSMutableAttributedString(string: text) attributedText.addAttribute(NSUnderlineStyleAttributeName, value:NSUnderlineStyle.StyleSingle.rawValue, range: textRange) // Add other attributes if needed self.attributedText = attributedText } } }

Answer 2

Swift 5＆amp; 4.2一个班轮：

label.attributedText = NSAttributedString(string: "Text", attributes:
    [.underlineStyle: NSUnderlineStyle.single.rawValue])

Swift 4 one liner：

label.attributedText = NSAttributedString(string: "Text", attributes:
    [.underlineStyle: NSUnderlineStyle.styleSingle.rawValue])

Swift 3 one liner：

label.attributedText = NSAttributedString(string: "Text", attributes:
      [NSUnderlineStyleAttributeName: NSUnderlineStyle.styleSingle.rawValue])

Answer 3

如果您正在寻找一种没有继承的方法 -

swift 3/4

// in swift 4 - switch NSUnderlineStyleAttributeName with NSAttributedStringKey.underlineStyle
extension UILabel {
    func underline() {
        if let textString = self.text {
          let attributedString = NSMutableAttributedString(string: textString)
          attributedString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: NSRange(location: 0, length: attributedString.length - 1))
          attributedText = attributedString
        }
    }
}


extension UIButton {
  func underline() {
    let attributedString = NSMutableAttributedString(string: (self.titleLabel?.text!)!)
    attributedString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.styleSingle.rawValue, range: NSRange(location: 0, length: (self.titleLabel?.text!.characters.count)!))
    self.setAttributedTitle(attributedString, for: .normal)
  }
}

Answer 4

您可以使用Interface Builder为UILabel文字加下划线。

以下是我的回答链接：Adding underline attribute to partial text UILabel in storyboard

Answer 5

对 Swift 4 和 Xcode 9 中的Shlome答案稍作解决。

extension UILabel {
    func underline() {
        if let textString = self.text {
            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(NSAttributedStringKey.underlineStyle,
                                          value: NSUnderlineStyle.styleSingle.rawValue,
                                          range: NSRange(location: 0, length: attributedString.length - 1))
            attributedText = attributedString
        }
    }
}

    extension UIButton {
        func underline() {
            let attributedString = NSMutableAttributedString(string: (self.titleLabel?.text!)!)
            attributedString.addAttribute(NSAttributedStringKey.underlineStyle,
                                          value: NSUnderlineStyle.styleSingle.rawValue,
                                          range: NSRange(location: 0, length: (self.titleLabel?.text!.count)!))
            self.setAttributedTitle(attributedString, for: .normal)
        }
    }

Answer 6

Swift 4：

1- 创建字符串扩展以获取attributedText。

2- 使用

扩展：

import UIKit
extension String {
   func getUnderLineAttributedText() -> NSAttributedString {
       return NSMutableAttributedString(string: self, attributes: [.underlineStyle: NSUnderlineStyle.styleSingle.rawValue])
   }
}

如何在buttton上使用它：

if let title = button.titleLabel?.text{
    button.setAttributedTitle(title.getUnderLineAttributedText(), for: .normal)
}

如何在标签上使用它：

if let title = label.text{    
   label.attributedText = title.getUnderLineAttributedText()
}

或 Stoyboard version

Answer 7

Swift 4 更改。记得使用 NSUnderlineStyle.styleSingle.rawValue 而不是 NSUnderlineStyle.styleSingle 。

   'let attributedString = NSAttributedString(string: "Testing")
    let textRange = NSMakeRange(0, attributedString.length)
    let underlinedMessage = NSMutableAttributedString(attributedString: attributedString)
    underlinedMessage.addAttribute(NSAttributedStringKey.underlineStyle,
                                   value:NSUnderlineStyle.styleSingle.rawValue,
                                   range: textRange)
    label.attributedText = underlinedMessage

`

Answer 8

上面的答案导致我的构建环境出错。

这在Swift 4.0中不起作用：

attributedText.addAttribute(NSUnderlineStyleAttributeName, 
                            value: NSUnderlineStyle.styleSingle.rawValue, 
                            range: textRange)

请改为尝试：

attributedText.addAttribute(NSAttributedStringKey.underlineStyle,
                            value: NSUnderlineStyle.styleSingle.rawValue,
                            range: textRange)

希望这有助于某人。

Answer 9

// Swift 4版

 let attributedString  = NSMutableAttributedString(string: "Your Text Here", attributes: [NSAttributedStringKey.underlineStyle : true])

self.yourlabel.attributedText = attributedString

Answer 10

Swift 4.2

中的相同答案

对于 UILable

extension UILabel {
    func underline() {
        if let textString = self.text {
            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(NSAttributedString.Key.underlineStyle,
                                          value: NSUnderlineStyle.single.rawValue,
                                          range: NSRange(location: 0, length: textString.count))
            self.attributedText = attributedString
        }
    }
}

像下面一样呼叫 UILabel

myLable.underline()

对于 UIButton

extension UIButton {
    func underline() {
        if let textString = self.titleLabel?.text {

            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(NSAttributedString.Key.underlineStyle,
                                          value: NSUnderlineStyle.single.rawValue,
                                          range: NSRange(location: 0, length: textString.count))
            self.setAttributedTitle(attributedString, for: .normal)
        }

    }
}

按如下所示呼叫 UIButton

myButton.underline()

我调查了以上答案，其中一些是强制展开 text 值的。我建议通过安全包装来获取价值。这将避免在nil值的情况下崩溃。希望这会有所帮助：）

Answer 11

快速4，4.2和5

value match {
   case Init(ackTo) => // or case d: Init and use d.ackTo
    ???
   case Complete =>
    ??? 
   case Fail(ex) =>
    ???     
   case SapMessage(ackTo, msg) =>
    ???    
}

我需要在UILabel中加下划线。因此，找到范围并设置属性。

  @IBOutlet weak var lblUnderLine: UILabel!

输出

Answer 12

对于Swift 2.3

extension UIButton {
    func underline() {
        let attributedString = NSMutableAttributedString(string: (self.titleLabel?.text!)!)
        attributedString.addAttribute(NSUnderlineStyleAttributeName, value: NSUnderlineStyle.StyleSingle.rawValue, range: NSRange(location: 0, length: (self.titleLabel?.text!.characters.count)!))
        self.setAttributedTitle(attributedString, forState: .Normal)
    }
}

并在ViewController中

@IBOutlet var yourButton: UIButton!

在ViewDidLoad方法或函数中只需编写

yourButton.underline()

它会为按钮的标题加下划线

Answer 13

为句子中的多个字符串加上下划线。

extension UILabel {
    func underlineMyText(range1:String, range2:String) {
        if let textString = self.text {

            let str = NSString(string: textString)
            let firstRange = str.range(of: range1)
            let secRange = str.range(of: range2)
            let attributedString = NSMutableAttributedString(string: textString)
            attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: firstRange)
            attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: secRange)
            attributedText = attributedString
        }
    }
}

通过这种方式使用。

    lbl.text = "By continuing you agree to our Terms of Service and Privacy Policy."
    lbl.underlineMyText(range1: "Terms of Service", range2: "Privacy Policy.")

Answer 14

如果您只想将标签的一半作为下划线，则也可以使用此功能：-//对于Swift 4.0 +

let attributesForUnderLine: [NSAttributedString.Key: Any] = [
            .font: UIFont(name: AppFont.sourceSansPro_Regular, size: 12) ?? UIFont.systemFont(ofSize: 11),
            .foregroundColor: UIColor.blue,
            .underlineStyle: NSUnderlineStyle.single.rawValue]

        let attributesForNormalText: [NSAttributedString.Key: Any] = [
            .font: UIFont(name: AppFont.sourceSansPro_Regular, size: 12) ?? UIFont.systemFont(ofSize: 11),
            .foregroundColor: AppColors.ColorText_787878]

        let textToSet = "Want to change your preferences? Edit Now"
        let rangeOfUnderLine = (textToSet as NSString).range(of: "Edit Now")
        let rangeOfNormalText = (textToSet as NSString).range(of: "Want to change your preferences?")

        let attributedText = NSMutableAttributedString(string: textToSet)
        attributedText.addAttributes(attributesForUnderLine, range: rangeOfUnderLine)
        attributedText.addAttributes(attributesForNormalText, range: rangeOfNormalText)
        yourLabel.attributedText = attributedText

Answer 15

为Swift 5的UIbutton设置和删除下划线的类。希望对您有所帮助

import Foundation
   import UIKit

   class UiUtil {

       static let underlineThickness = 2
    
       class func removeUnderlineFromButton( _ button:UIButton ) {
          if let str = button.titleLabel?.attributedText {
            let attributedString = NSMutableAttributedString( attributedString: str )
            attributedString.removeAttribute(.underlineStyle, range: 
   NSRange.init(location: 0, length: attributedString.length))
            button.setAttributedTitle(attributedString, for: .normal)
         }
      }

    class func setUnderlineFromButton( _ button:UIButton ) {
        if let str = button.titleLabel?.attributedText {
            let attributedStringUnderline = NSMutableAttributedString( attributedString: 
    str  )
              attributedStringUnderline.addAttribute(
                NSAttributedString.Key.underlineStyle,
                value: underlineThickness,
                range: NSRange.init(location: 0, length: attributedStringUnderline.length)
              )
              button.setAttributedTitle(attributedStringUnderline, for: .normal)
           }
      }

   }

Answer 16

我的应用中使用了算法。在此算法中，即使单词之间有空格，您也可以在子字符串下划线

extension NSMutableAttributedString{

    static func  findSubStringAndUnderlineIt(subStringToBeFound : String,totalString : String)->  NSMutableAttributedString?{
        
        let attributedString = NSMutableAttributedString(string: totalString)

        var spaceCount = 0
        
        if subStringToBeFound.contains(" "){
            spaceCount = subStringToBeFound.components(separatedBy:" ").count-1
        }

        
        if  let range = attributedString.string.range(of: subStringToBeFound, options: .caseInsensitive){
        
            attributedString.addAttribute(NSAttributedString.Key.underlineStyle, value: NSUnderlineStyle.single.rawValue, range: NSMakeRange((range.lowerBound.utf16Offset(in: subStringToBeFound)) ,(range.upperBound.utf16Offset(in: subStringToBeFound)) +
            spaceCount))
                return attributedString
        }
        return attributedString
        
    }
    
}

在使用的部分

 lblWarning.attributedText = NSMutableAttributedString.findSubStringAndUnderlineIt(subStringToBeFound:"Not: Sadece uygulamanın reklamları kaldırılacaktır.", totalString: lblWarning.text!)

如何在swift中强调UILabel？

16 个答案:

swift 3/4