小编Jui*_*uio的帖子

我正在尝试在后栏按钮项目上设置属性字符串.
这是我第一次尝试归因于字符串.
这是代码:

    self.navigationItem.hidesBackButton = true
    let barButtonBackStr = "< Back"
    var attributedBarButtonBackStr = NSMutableAttributedString(string: barButtonBackStr as String)
    attributedBarButtonBackStr.addAttribute(NSFontAttributeName,
        value: UIFont(
            name: "AmericanTypewriter-Bold",
            size: 18.0)!,
        range: NSRange(
            location:0,
            length:1))
    let newBackButton = UIBarButtonItem(title: attributedBarButtonBackStr, style: UIBarButtonItemStyle.Plain, target: self, action: "barButtonBack:")
    self.navigationItem.leftBarButtonItem = newBackButton

这导致Xcode中出现以下错误.

无法使用类型为'(title:NSMutableAttributedString,style:UIBarButtonItemStyle,target:CombatOutcomeViewController,action:String)的参数列表调用类型'UIBarButtonItem'的初始值设定项'

任何人都知道如何做到这一点？谢谢.