【iOS开发】UILabel显示html标签的高度计算

//富文本
        let attrStr = try! NSMutableAttributedString(
            data: (answer.content.data(using: .unicode, allowLossyConversion: true)!),
            options:[.documentType: NSAttributedString.DocumentType.html,
                     .characterEncoding: String.Encoding.utf8.rawValue],
            documentAttributes: nil)
        //行高
        let paraph = NSMutableParagraphStyle()
        paraph.lineSpacing = 8
        attrStr.addAttributes([NSAttributedStringKey.paragraphStyle:paraph],
                              range: NSMakeRange(0, attrStr.length))
        
        self.answerLabel.attributedText = attrStr
        //计算高度
        
        let size:CGRect = attrStr.boundingRect(with:  CGSize(width: SCREENWIDTH-32, height: CGFloat(MAXFLOAT)), options: NSStringDrawingOptions(rawValue: NSStringDrawingOptions.usesLineFragmentOrigin.rawValue), context: nil)