ios - 快速更改 titleTextAttribute

Question

自从我更新 xcode 以来，我似乎无法更改 titleTextAttribute。现在，当我使用以下代码时，出现此错误:

could not find an overload init that accepts this supplied arguments

appDelegate中的代码:

UINavigationBar.appearance().titleTextAttributes = [NSFontAttributeName: UIFont(name: "Ubuntu", size: 17), NSForegroundColorAttributeName:UIColor.whiteColor()]
UIBarButtonItem.appearance().setTitleTextAttributes([NSFontAttributeName: UIFont(name: "Ubuntu-Light", size: 15), NSForegroundColorAttributeName:UIColor.whiteColor()], forState: UIControlState.Normal)

Answer 1

最近发生了变化，因此 UIFont(name:size:) 返回一个可选的 UIFont 实例。你需要打开它们才能让它工作。使用 ! 是最简单的方法，但如果字体不在系统中，则会导致崩溃。尝试类似的东西:

let navbarFont = UIFont(name: "Ubuntu", size: 17) ?? UIFont.systemFontOfSize(17)
let barbuttonFont = UIFont(name: "Ubuntu-Light", size: 15) ?? UIFont.systemFontOfSize(15)

UINavigationBar.appearance().titleTextAttributes = [NSFontAttributeName: navbarFont, NSForegroundColorAttributeName:UIColor.whiteColor()]
UIBarButtonItem.appearance().setTitleTextAttributes([NSFontAttributeName: barbuttonFont, NSForegroundColorAttributeName:UIColor.whiteColor()], forState: UIControlState.Normal)