在swift中使用属性字符串使文本变粗

Question

我有这样的字符串

var str = "@text1 this is good @text1"

现在换成text1另一个字符串,比方说t 1.我能够替换文本,但我无法加粗.我想加粗新字符串t 1,以便最终输出为:

@t 1这是好的@t 1

我该怎么做？

我看到的所有示例都在Objective-C中,但我想在Swift中进行.

提前致谢.

Answer 1

这是在单个标签中组合粗体和普通文本的简洁方法.

延期:

Swift 3.0

extension NSMutableAttributedString {
    @discardableResult func bold(_ text:String) -> NSMutableAttributedString {
        let attrs:[String:AnyObject] = [NSFontAttributeName: UIFont(name: "AvenirNext-Medium", size: 12)!]
        let boldString = NSMutableAttributedString(string: text, attributes:attrs)
        self.append(boldString)
        return self
    }

    @discardableResult func normal(_ text:String)->NSMutableAttributedString {
        let normal =  NSAttributedString(string: text)
        self.append(normal)
        return self
    }
}

斯威夫特4

extension NSMutableAttributedString {
    @discardableResult func bold(_ text: String) -> NSMutableAttributedString {
        let attrs: [NSAttributedStringKey: Any] = [.font: UIFont(name: "AvenirNext-Medium", size: 12)!]
        let boldString = NSMutableAttributedString(string:text, attributes: attrs)
        append(boldString)

        return self
    }

    @discardableResult func normal(_ text: String) -> NSMutableAttributedString {
        let normal = NSAttributedString(string: text)
        append(normal)

        return self
    }
}

用法:

let formattedString = NSMutableAttributedString()
formattedString
    .bold("Bold Text")
    .normal(" Normal Text ")
    .bold("Bold Text")

let lbl = UILabel()
lbl.attributedText = formattedString

结果:

粗体文本普通文本粗体文本

Answer 2

var normalText = "Hi am normal"

var boldText  = "And I am BOLD!"

var attributedString = NSMutableAttributedString(string:normalText)

var attrs = [NSFontAttributeName : UIFont.boldSystemFont(ofSize: 15)]
var boldString = NSMutableAttributedString(string: boldText, attributes:attrs)

attributedString.append(boldString)

如果要将其分配给标签:

yourLabel.attributedText = attributedString

Answer 3

编辑/更新:Xcode 8.3.2•Swift 3.1

如果您了解HTML和CSS,则可以使用它轻松控制属性字符串的字体样式,颜色和大小,如下所示:

extension String {
    var html2AttStr: NSAttributedString? {
        return try? NSAttributedString(data: Data(utf8), options: [NSDocumentTypeDocumentAttribute: NSHTMLTextDocumentType, NSCharacterEncodingDocumentAttribute: String.Encoding.utf8.rawValue], documentAttributes: nil)
    }
}

"<style type=\"text/css\">#red{color:#F00}#green{color:#0F0}#blue{color: #00F; font-weight: Bold; font-size: 32}</style><span id=\"red\" >Red,</span><span id=\"green\" > Green </span><span id=\"blue\">and Blue</span>".html2AttStr

Answer 4

如果您正在使用本地化字符串,则可能无法依赖始终位于句子末尾的粗体字符串.如果是这种情况,那么以下效果很好:

例如,查询"blah"与任何项目都不匹配

/* Create the search query part of the text, e.g. "blah". 
   The variable 'text' is just the value entered by  the user. */
let searchQuery = "\"\(text)\""

/* Put the search text into the message */
let message = "Query \(searchQuery). does not match any items"

/* Find the position of the search string. Cast to NSString as we want
   range to be of type NSRange, not Swift's Range<Index> */
let range = (message as NSString).rangeOfString(searchQuery)

/* Make the text at the given range bold. Rather than hard-coding a text size,
   Use the text size configured in Interface Builder. */
let attributedString = NSMutableAttributedString(string: message)
attributedString.addAttribute(NSFontAttributeName, value: UIFont.boldSystemFontOfSize(label.font.pointSize), range: range)

/* Put the text in a label */
label.attributedText = attributedString

Answer 5

Swift 4 及更高版本

对于 Swift 4 及更高版本，这是一个好方法：

    let attributsBold = [NSAttributedString.Key.font : UIFont.systemFont(ofSize: 16, weight: .bold)]
    let attributsNormal = [NSAttributedString.Key.font : UIFont.systemFont(ofSize: 16, weight: .regular)]
    var attributedString = NSMutableAttributedString(string: "Hi ", attributes:attributsNormal)
    let boldStringPart = NSMutableAttributedString(string: "John", attributes:attributsBold)
    attributedString.append(boldStringPart)
  
    yourLabel.attributedText = attributedString

在标签中，文本看起来像：“嗨，约翰”

Answer 6

这是我提出的最佳方式.添加一个可以从任何地方调用的函数,并将其添加到一个没有像Constants.swift这样的类的文件中,然后你可以通过调用一行代码在很多情况下在任何字符串中加入单词:

要进入constants.swift文件:

import Foundation
import UIKit

func addBoldText(fullString: NSString, boldPartOfString: NSString, font: UIFont!, boldFont: UIFont!) -> NSAttributedString {
   let nonBoldFontAttribute = [NSFontAttributeName:font!]
   let boldFontAttribute = [NSFontAttributeName:boldFont!]
   let boldString = NSMutableAttributedString(string: fullString as String, attributes:nonBoldFontAttribute)
   boldString.addAttributes(boldFontAttribute, range: fullString.rangeOfString(boldPartOfString as String))
   return boldString
}

然后你可以为任何UILabel调用这一行代码:

self.UILabel.attributedText = addBoldText("Check again in 30 DAYS to find more friends", boldPartOfString: "30 DAYS", font: normalFont!, boldFont: boldSearchFont!)


//Mark: Albeit that you've had to define these somewhere:

let normalFont = UIFont(name: "INSERT FONT NAME", size: 15)
let boldFont = UIFont(name: "INSERT BOLD FONT", size: 15)

Answer 7

我扩展了David West的好答案,以便您可以输入一个字符串并告诉它您想要鼓励的所有子字符串:

func addBoldText(fullString: NSString, boldPartsOfString: Array<NSString>, font: UIFont!, boldFont: UIFont!) -> NSAttributedString {
    let nonBoldFontAttribute = [NSFontAttributeName:font!]
    let boldFontAttribute = [NSFontAttributeName:boldFont!]
    let boldString = NSMutableAttributedString(string: fullString as String, attributes:nonBoldFontAttribute)
    for i in 0 ..< boldPartsOfString.count {
        boldString.addAttributes(boldFontAttribute, range: fullString.rangeOfString(boldPartsOfString[i] as String))
    }
    return boldString
}

然后像这样调用它:

let normalFont = UIFont(name: "Dosis-Medium", size: 18)
let boldSearchFont = UIFont(name: "Dosis-Bold", size: 18)
self.UILabel.attributedText = addBoldText("Check again in 30 days to find more friends", boldPartsOfString: ["Check", "30 days", "find", "friends"], font: normalFont!, boldFont: boldSearchFont!)

这将鼓励您想要在给定字符串中加粗的所有子字符串

Answer 8

基于Jeremy Bader和David West的出色答案，Swift 3扩展：

extension String {
    func withBoldText(boldPartsOfString: Array<NSString>, font: UIFont!, boldFont: UIFont!) -> NSAttributedString {
        let nonBoldFontAttribute = [NSFontAttributeName:font!]
        let boldFontAttribute = [NSFontAttributeName:boldFont!]
        let boldString = NSMutableAttributedString(string: self as String, attributes:nonBoldFontAttribute)
        for i in 0 ..< boldPartsOfString.count {
            boldString.addAttributes(boldFontAttribute, range: (self as NSString).range(of: boldPartsOfString[i] as String))
        }
        return boldString
    }
}

用法：

let label = UILabel()
let font = UIFont(name: "AvenirNext-Italic", size: 24)!
let boldFont = UIFont(name: "AvenirNext-BoldItalic", size: 24)!
label.attributedText = "Make sure your face is\nbrightly and evenly lit".withBoldText(
    boldPartsOfString: ["brightly", "evenly"], font: font, boldFont: boldFont)

Answer 9

用法....

let attrString = NSMutableAttributedString()
            .appendWith(weight: .semibold, "almost bold")
            .appendWith(color: .white, weight: .bold, " white and bold")
            .appendWith(color: .black, ofSize: 18.0, " big black")

两分...

extension NSMutableAttributedString {

    @discardableResult func appendWith(color: UIColor = UIColor.darkText, weight: UIFont.Weight = .regular, ofSize: CGFloat = 12.0, _ text: String) -> NSMutableAttributedString{
        let attrText = NSAttributedString.makeWith(color: color, weight: weight, ofSize:ofSize, text)
        self.append(attrText)
        return self
    }

}
extension NSAttributedString {

    public static func makeWith(color: UIColor = UIColor.darkText, weight: UIFont.Weight = .regular, ofSize: CGFloat = 12.0, _ text: String) -> NSMutableAttributedString {

        let attrs = [NSAttributedStringKey.font: UIFont.systemFont(ofSize: ofSize, weight: weight), NSAttributedStringKey.foregroundColor: color]
        return NSMutableAttributedString(string: text, attributes:attrs)
    }
}

Answer 10

接受Prajeet Shrestha在此线程中的响应是有效的，如果已知 Label 和字体的特征，我想使用 Label 扩展他的解决方案。

斯威夫特 4

extension NSMutableAttributedString {

    @discardableResult func normal(_ text: String) -> NSMutableAttributedString {
        let normal = NSAttributedString(string: text)
        append(normal)

        return self
    }

    @discardableResult func bold(_ text: String, withLabel label: UILabel) -> NSMutableAttributedString {

        //generate the bold font
        var font: UIFont = UIFont(name: label.font.fontName , size: label.font.pointSize)!
        font = UIFont(descriptor: font.fontDescriptor.withSymbolicTraits(.traitBold) ?? font.fontDescriptor, size: font.pointSize)

        //generate attributes
        let attrs: [NSAttributedStringKey: Any] = [NSAttributedStringKey.font: font]
        let boldString = NSMutableAttributedString(string:text, attributes: attrs)

        //append the attributed text
        append(boldString)

        return self
    }
}