swift3.0 label行高extension封装

class func linespacing(_ content: String,_ space: Int) -> NSAttributedString {
        let attributedString:NSMutableAttributedString = NSMutableAttributedString(string: content)
        let paragraphStyle = NSMutableParagraphStyle()
        paragraphStyle.linespacing = CGFloat(space)
        paragraphStyle.alignment = .right
        attributedString.addAttribute(NSParagraphStyleAttributeName,value: paragraphStyle,range: NSMakeRange(0,content.characters.count))
        return attributedString
    }