IOS Swift3.1 获得文本宽度

func getStringRect(text:String, font:UIFont) -> CGRect {

        let nsText: NSString = NSString( string: text )
        let size:CGSize = CGSize(width: UIScreen.main.bounds.width, height: 0)
        let options:NSStringDrawingOptions =  NSStringDrawingOptions.usesFontLeading
        let boundRec = nsText.boundingRect(with: size, options: options, attributes: [NSFontAttributeName: font], context: nil)
        return boundRec

    }

使用范例：

        let text: String = "abcabc"
        let font: UIFont = UIFont.systemFont(ofSize: 14)
        let cgRect: CGRect = getStringRect(text: text, font: font )
        print( cgRect.width, cgRect.height )