讓圖示在AttributedText上下置中

https://stackoverflow.com/questions/26105803/center-nstextattachment-image-next-to-single-line-uilabel

let iconImage = UIImage(named: "icon.png")!
var icon = NSTextAttachment()
icon.bounds = CGRect(x: 0, y: (titleFont.capHeight - iconImage.size.height).rounded() / 2, width: iconImage.size.width, height: iconImage.size.height)
icon.image = iconImage
let iconString = NSAttributedString(attachment: icon)
titleText.append(iconString)