在 SwiftUI 中将部分文本加粗

Question

我想知道如何在 SwiftUI 中仅将文本的部分加粗，而将其余部分保持“常规”。

我目前有：

Text("Coronavirus Disease of 2019")

我希望它打印出 COronaVirus Disease of 2019 and have'只能将某些部分加粗。

Answer 1

斯威夫特 5.5

Foundation 支持 Markdown。

---

在要加粗的字符周围添加双星号 (**)。

Text("**CO**rona**V**irus **D**isease of 20**19**")

在要斜体的字符周围添加下划线。

Text("Is this text _emphasized_?")

Answer 2

如果你不需要在这里翻译它是可能的快速变体

Text("CO").bold() + Text("rona") + Text("VI").bold() + 
    Text("rus Disease of 20") + Text("19").bold()

替代方法是将 NSAttributedString 与 UIViewRepresentable 或 UILabel 一起使用。

Answer 3

添加到 Asperi 的出色答案的快速说明，如果您需要对文本应用框架或填充修饰符，则需要先对文本进行分组，然后将修饰符添加到组中。

Group { Text("CO").bold() + Text("rona") + Text("VI").bold() + Text("rus Disease of 20") + Text("19").bold() }.frame(width: 100, height: 100).padding(.horizontal)

Answer 4

这个问题出现了很多，对于一个没有 Objective-C 背景的 Swift 新手来说，解决方案是不情愿的。上面的几个答案都很好，但总结一下问题的最佳解决方案，

Group {
    Text("CO").bold() +
    Text("rona") +
    Text("V").bold() +
    Text("irus ") +
    Text("D").bold() +
    Text("isease of 20") +
    Text("19").bold()
}
.font(.caption)
.frame(width: 300)

（Group{} 是我的秘诀）

Answer 5

Swift 5、iOS 13

这篇文章是关于改变字符文本的颜色，但你同样可以应用它使用 [a bit mask] 的技术来使某些字符加粗、闪烁、动画等等？

https://medium.com/@marklucking/an-interesting-challenge-with-swiftui-9ebb26e77376

你需要关注的两个核心部分是..

ForEach((0 ..< letter.count), id: \.self) { column in
          Text(letter[column])
            .foregroundColor(colorCode(gate: Int(self.gate), no: column) ? Color.black: Color.red)
            .font(Fonts.futuraCondensedMedium(size: fontSize))

        }

还有这个用来掩盖文字的……

func colorCode(gate:Int, no:Int) -> Bool {

  let bgr = String(gate, radix:2).pad(with: "0", toLength: 16)
  let bcr = String(no, radix:2).pad(with: "0", toLength: 16)
  let binaryColumn = 1 << no - 1

  let value = UInt64(gate) & UInt64(binaryColumn)
  let vr = String(value, radix:2).pad(with: "0", toLength: 16)

  print("bg ",bgr," bc ",bcr,vr)
  return value > 0 ? true:false
}

Answer 6

@mahan 提出的解决方案很棒，但它有一个限制，即它在 iOS 15 上运行良好，但在 iOS 14 上却不行。

所以我认为对于那些需要支持 iOS 14 的人来说这是一个更好的解决方案，该解决方案是从这个网站复制的： https://www.avanderlee.com/swiftui/text-weight-combinations/

最终代码如下所示：

    @main
struct RichTextApp: App {
    var body: some Scene {
        WindowGroup {
            RichText("SwiftLee - A *weekly blog* about Swift, iOS and Xcode *Tips and Tricks*")
                .padding()
                .multilineTextAlignment(.center)
        }
    }
}

（您可以自定义字体并在文本中添加变量，例如：）

RichText(" ... *\(viewModel.title)* ...")

代码是：

import SwiftUI

struct RichText: View {

    struct Element: Identifiable {
        let id = UUID()
        let content: String
        let isBold: Bool

        init(content: String, isBold: Bool) {
            var content = content.trimmingCharacters(in: .whitespacesAndNewlines)

            if isBold {
                content = content.replacingOccurrences(of: "*", with: "")
            }

            self.content = content
            self.isBold = isBold
        }
    }

    let elements: [Element]

    init(_ content: String) {
        elements = content.parseRichTextElements()
    }

    var body: some View {
        var content = text(for: elements.first!)
        elements.dropFirst().forEach { (element) in
            content = content + self.text(for: element)
        }
        return content
    }
    
    private func text(for element: Element) -> Text {
        let postfix = shouldAddSpace(for: element) ? " " : ""
        if element.isBold {
            return Text(element.content + postfix)
                .fontWeight(.bold)
        } else {
            return Text(element.content + postfix)
        }
    }

    private func shouldAddSpace(for element: Element) -> Bool {
        return element.id != elements.last?.id
    }
    
}



extension String {

    /// Parses the input text and returns a collection of rich text elements.
    /// Currently supports asterisks only. E.g. "Save *everything* that *inspires* your ideas".
    ///
    /// - Returns: A collection of rich text elements.
    func parseRichTextElements() -> [RichText.Element] {
        let regex = try! NSRegularExpression(pattern: "\\*{1}(.*?)\\*{1}")
        let range = NSRange(location: 0, length: count)

        /// Find all the ranges that match the regex *CONTENT*.
        let matches: [NSTextCheckingResult] = regex.matches(in: self, options: [], range: range)
        let matchingRanges = matches.compactMap { Range<Int>($0.range) }

        var elements: [RichText.Element] = []

        // Add the first range which might be the complete content if no match was found.
        // This is the range up until the lowerbound of the first match.
        let firstRange = 0..<(matchingRanges.count == 0 ? count : matchingRanges[0].lowerBound)

        self[firstRange].components(separatedBy: " ").forEach { (word) in
            guard !word.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else { return }
            elements.append(RichText.Element(content: String(word), isBold: false))
        }

        // Create elements for the remaining words and ranges.
        for (index, matchingRange) in matchingRanges.enumerated() {
            let isLast = matchingRange == matchingRanges.last

            // Add an element for the matching range which should be bold.
            let matchContent = self[matchingRange]
            elements.append(RichText.Element(content: matchContent, isBold: true))

            // Add an element for the text in-between the current match and the next match.
            let endLocation = isLast ? count : matchingRanges[index + 1].lowerBound
            let range = matchingRange.upperBound..<endLocation
            self[range].components(separatedBy: " ").forEach { (word) in
                guard !word.trimmingCharacters(in: .whitespacesAndNewlines).isEmpty else { return }
                elements.append(RichText.Element(content: String(word), isBold: false))
            }
        }

        return elements
    }

    /// - Returns: A string subscript based on the given range.
    subscript(range: Range<Int>) -> String {
        let startIndex = index(self.startIndex, offsetBy: range.lowerBound)
        let endIndex = index(self.startIndex, offsetBy: range.upperBound)
        return String(self[startIndex..<endIndex])
    }
}