(UILabel) - 测算Label显示文字所需高度

    // MARK: - 测算Label显示文字所需高度
    /// 测算Label显示文字所需高度
    ///
    /// - Parameters:
    ///   - width: 给定宽度
    ///   - font: 字号
    ///   - lineSpacing: 行间距
    ///   - kern: 字间距
    ///   - text: 文字
    /// - Returns: 高度
    public func getSpaceLabelHeight(byWith width: CGFloat, font: UIFont, lineSpacing: CGFloat, kern: CGFloat, text: String) -> CGFloat{
        
        // 设置行间距
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.lineSpacing = lineSpacing
        
        // 设置字体/字间距
        let attributes: [NSAttributedStringKey : Any] = [.paragraphStyle : paragraphStyle,
                                                         .font : font,
                                                         .kern : kern]
        
        // 计算label字符串的高度
        let rect: CGRect = text.boundingRect(with: CGSize(width: width, height: CGFloat(MAXFLOAT)),
                                             options: .usesLineFragmentOrigin,
                                             attributes: attributes,
                                             context: nil)
        
        return rect.size.height
    }