Xcode HTML到字符串返回零？- SWIFT 3

Question

public func setHtmlBody(_ body: String, bounds: CGRect = UIScreen.main.bounds) -> String {

    let font = "-apple-system"
    let fontSize = 19
    let fontColor = "#000000"
    let lineHeight = 25
    let imageWidth = bounds.width - 40
    let margin = 20
    let codeStyle = "pre[class*=\"language-\"]{background:white;border-radius:14px;color:black;display:block;font-size:16px;font-weight:500;padding:20px;overflow-x:auto;white-space:pre-wrap;line-height:130%;}pre.language-coffeescript .token.comment{color:#6a7576}pre.language-coffeescript .token.string{color:#8ADC64}pre.language-coffeescript .token.number,pre.language-coffeescript .token.operator{color:#a580f8}pre.language-coffeescript .token.keyword,pre.language-coffeescript .token.class-name,pre.language-coffeescript .token.function{color:#8df}pre.language-swift .token.comment{color:#690}pre.language-swift .token.string{color:#ee433f}pre.language-swift .token.keyword{color:#C945A7}pre.language-swift .token.number,pre.language-swift .token.function,pre.language-swift .token.builtin,pre.language-swift .token.class-name{color:#5C2699}"

    let htmlString = "<style>p, li { font-family:\"\(font)\"; color: \(fontColor); font-size:\(fontSize)px; line-height:\(lineHeight)px } p { margin: \(margin)px 0; } img { max-width: \(imageWidth)px; } #p { font-weight: bold; font-size: 24px; line-height: 130%; margin: 50px 20px; } ul li, ol li { margin: 20px 0; font-weight: bold; } \(codeStyle)</style>\(body)"

    return htmlString
}

我正在使用 swift 3。为什么该函数将我返回为 Nil？

签名：

bodyAttributedString = setHtmlBody(sectionBody).htmlToAttributedString

Answer 1

这将是htmlToAttributedString 功能所有其他工作正常的问题。我用类似的方法尝试过，它对我来说非常有效

请检查...

扩展将html作为属性字符串

extension Data {
    var htmlToAttributedString: NSAttributedString? {
        do {
            return try NSAttributedString(data: self, options: [.documentType: NSAttributedString.DocumentType.html, .characterEncoding: String.Encoding.utf8.rawValue], documentAttributes: nil)
        } catch {
            print("error:", error)
            return  nil
        }
    }
    var html2String: String {
        return htmlToAttributedString?.string ?? ""
    }
}

extension String {
    var htmlToAttributedString: NSAttributedString? {
        return Data(utf8).htmlToAttributedString
    }
    var html2String: String {
        return htmlToAttributedString?.string ?? ""
    }
}

HTML 字符串构建函数

public func setHtmlBody(_ body: String, bounds: CGRect = UIScreen.main.bounds) -> String {

    let font = "-apple-system"
    let fontSize = 19
    let fontColor = "#000000"
    let lineHeight = 25
    let imageWidth = bounds.width - 40
    let margin = 20
    let codeStyle = "pre[class*=\"language-\"]{background:white;border-radius:14px;color:black;display:block;font-size:16px;font-weight:500;padding:20px;overflow-x:auto;white-space:pre-wrap;line-height:130%;}pre.language-coffeescript .token.comment{color:#6a7576}pre.language-coffeescript .token.string{color:#8ADC64}pre.language-coffeescript .token.number,pre.language-coffeescript .token.operator{color:#a580f8}pre.language-coffeescript .token.keyword,pre.language-coffeescript .token.class-name,pre.language-coffeescript .token.function{color:#8df}pre.language-swift .token.comment{color:#690}pre.language-swift .token.string{color:#ee433f}pre.language-swift .token.keyword{color:#C945A7}pre.language-swift .token.number,pre.language-swift .token.function,pre.language-swift .token.builtin,pre.language-swift .token.class-name{color:#5C2699}"

    let htmlString = "<style>p, li { font-family:\"\(font)\"; color: \(fontColor); font-size:\(fontSize)px; line-height:\(lineHeight)px } p { margin: \(margin)px 0; } img { max-width: \(imageWidth)px; } #p { font-weight: bold; font-size: 24px; line-height: 130%; margin: 50px 20px; } ul li, ol li { margin: 20px 0; font-weight: bold; } \(codeStyle)</style>\(body)"
    return htmlString
}

演示文稿

override func viewDidLoad() {
    super.viewDidLoad()

    let body = "<p>Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.</p>"

    let htmlString = setHtmlBody(body)


    if let attributedString = htmlString.htmlToAttributedString {
        self.labelHTML.attributedText = attributedString
    }
 }

输出