UILabel设置多种字体颜色、尺寸

let str1 = NSMutableAttributedString(string: "每积累签到5天送50个名额")
// 设置数字5为红色
str1.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range: NSMakeRange(5, 1))
// 设置数字5的字体为：Arial, size为20
str1.addAttribute(NSFontAttributeName, value: UIFont(name: "Arial", size: 20)!, range: NSMakeRange(5, 1))
// 设置数字50为红色
str1.addAttribute(NSForegroundColorAttributeName, value: UIColor.redColor(), range: NSMakeRange(8, 2))
// 添加下划线
str.addAttribute(NSUnderlineStyleAttributeName, value: NSNumber(integer: NSUnderlineStyle.StyleSingle.rawValue), range: NSMakeRange(3, str.length - 3))
detailLbl2.attributedText = str1