您好，我正在尝试在Swift3中使用addAttribute。我只想将IDNAME设置为粗体。这是我正在尝试的。letboldUsername=NSMutableAttributedString(string:"IDNAMEhinice2meetyou:D#HELLOW")//boldUsername.addAttribute(NSFontAttributeName,value:UIFont(name:"SFUIText-Bold",size:14)!,range:(boldUsername.stringasNSString).range(of:""))boldUsername.add