嵌套的NSAttributedString

Question

我正在从我的Swift应用程序生成PDF发票。因为不是所有修补的地址都有相同的深度，所以我使用回车符来布局文本。例如，地址、日期、发票编号、主题行和叙述。这一切都工作得很好，但是，我想用粗体文本格式化主题行。我已经环顾了这个主题，却一无所获。本质上，我的问题是你可以嵌套NSAttributed字符串，这样我就可以用粗体格式设置主题行的格式，而不必创建另一个NSAttributed字符串，这将意味着我失去了布局规则？

这是我的代码

    let textFont = UIFont.systemFont(ofSize: 10.0, weight: .regular)
    let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = .natural
    paragraphStyle.lineBreakMode = .byWordWrapping
    let textAttributes = [NSAttributedString.Key.paragraphStyle: paragraphStyle,
                          NSAttributedString.Key.font: textFont,
                          NSAttributedString.Key.kern : -0.15] as [NSAttributedString.Key : Any]

    let attributedText = NSAttributedString(string: "\(billAddress)\r\r\r\("Invoice number:  \ . 
     (invoiceNumber)")\r\("Date:  \(mydate)")\r\r\r\("To")\r\r\(subjectline)\r\r\(narrative)", 
    attributes: 
    textAttributes as [NSAttributedString.Key : Any])

欢迎任何帮助/想法/解决方案

Answer 1

您可以使用NSMutableAttributedString，并使用.append(_:)方法追加字符串的不同部分。(https://developer.apple.com/documentation/foundation/nsmutableattributedstring/1417879-append)

你也可以看看https://github.com/Rightpoint/BonMot

Answer 2

  let paragraphStyle = NSMutableParagraphStyle()
    paragraphStyle.alignment = .natural
    paragraphStyle.lineBreakMode = .byWordWrapping
    let defaultAttributes: [NSAttributedString.Key: Any] = [NSAttributedString.Key.paragraphStyle: paragraphStyle,
                                                            NSAttributedString.Key.font: UIFont.systemFont(ofSize: 10.0, weight: .regular),
                                                            NSAttributedString.Key.kern : -0.15]

    let boldAttributes: [NSAttributedString.Key: Any] = [NSAttributedString.Key.paragraphStyle: paragraphStyle,
                                                         NSAttributedString.Key.font: UIFont.systemFont(ofSize: 10.0, weight: .bold),
                                                         NSAttributedString.Key.kern : -0.15]
    let attributedText = NSMutableAttributedString()

    attributedText.append(NSAttributedString(string: (billAddress), attributes: defaultAttributes))
    attributedText.append(NSAttributedString(string: "\r\r"))
    attributedText.append(NSAttributedString(string: "Invoice number:  \(invoiceNumber)", attributes: defaultAttributes))
    attributedText.append(NSAttributedString(string: "\r"))
    attributedText.append(NSAttributedString(string: "Date:  \(mydate)", attributes: defaultAttributes))
    attributedText.append(NSAttributedString(string: "\r\r"))
    attributedText.append(NSAttributedString(string: "To", attributes: defaultAttributes))
    attributedText.append(NSAttributedString(string: "\r\r"))
    attributedText.append(NSAttributedString(string: subjectline, attributes: boldAttributes))
    attributedText.append(NSAttributedString(string: "\r"))
    attributedText.append(NSAttributedString(string: narrative, attributes: defaultAttributes))

    let textRect = CGRect(x: 40, y: textTop, width: pageRect.width - 240,
                          height: pageRect.height - textTop - pageRect.height / 2 )
    attributedText.draw(in: textRect)