NSFontAttributeName未应用于NSAttributedString

Question

我目前正在使用此答案提供的此扩展程序将html转换为字符串中的字符串UITextView.一切都很完美,但由于某些奇怪的原因,NSFontAttributeName在此过程中不会应用于字符串.我有什么问题吗？(或者我应该在使用NSAttributedString后面的html解析字符串后应用？如果是这样,是否可以将属性应用于NSAttributeString？).

PS.使用时字体大小不会改变,html2String但html中的链接会被更长时间识别UITextView

extension String {

    var html2AttributedString: NSAttributedString? {
        guard
            let data = dataUsingEncoding(NSUTF8StringEncoding)
            else { return nil }
        do {
            return try NSAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding, NSFontAttributeName : UIFont.systemFontOfSize(17.0)], documentAttributes: nil)
        } catch let error as NSError {
            print(error.localizedDescription)
            return  nil
        }
    }
    var html2String: String {
        return html2AttributedString?.string ?? ""
    }
}
cell.desc.attributedText  = apiData[currentIndex].description!.html2AttributedString //Font attribute not recognized
cell.desc.text  = apiData[currentIndex].description!.html2String //Font recognized by links no longer recognized

Answer 1

我不确定为什么(可能是因为有一个范围)但是如果您首先创建一个NSMutableAttributedString然后添加UIFont属性它会起作用:

extension String {

    var html2AttributedString: NSMutableAttributedString? {
        guard
            let data = dataUsingEncoding(NSUTF8StringEncoding)
            else { return nil }
        do {
            let attrStr = try NSMutableAttributedString(data: data, options: [NSDocumentTypeDocumentAttribute:NSHTMLTextDocumentType,NSCharacterEncodingDocumentAttribute:NSUTF8StringEncoding], documentAttributes: nil)
            attrStr.addAttributes([NSFontAttributeName: UIFont.systemFontOfSize(17.0)], range: NSRange(location: 0, length: attrStr.length))
            return attrStr
        } catch let error as NSError {
            print(error.localizedDescription)
            return  nil
        }
    }
    var html2String: String {
        return html2AttributedString?.string ?? ""
    }
}