swift - 在 Swift 中使用 UIAlertController 更改警报的标题和消息字体

Question

我正在尝试更改使用 UIAlertController 显示的警报的标题和消息字体我正在尝试使用 NSAttributedStirng，但它给出了编译器错误，即无法采用 NSAttributed 字符串代替 Stirng我尝试了类似于 this 的东西

var title_attrs = [NSFontAttributeName : CustomFonts.HELVETICA_NEUE_MEDIUM_16]
var msg_attrs = [NSFontAttributeName : CustomFonts.HELVETICA_NEUE_REGULAR_14]
var title = NSMutableAttributedString(string:"Done", attributes:title_attrs)

var msg = NSMutableAttributedString(string:"The job is done ", attributes:msg_attrs)
let alertController = UIAlertController(title: title, message: title , preferredStyle: UIAlertControllerStyle.Alert)

有人可以指导我如何实现这一目标吗？

Answer 1

Swift 3 版本:

extension UIAlertController {
    func changeFont(view: UIView, font:UIFont) {
        for item in view.subviews {
            if item.isKind(of: UICollectionView.self) {
                let col = item as! UICollectionView
                for  row in col.subviews{
                    changeFont(view: row, font: font)
                }
            }
            if item.isKind(of: UILabel.self) {
                let label = item as! UILabel
                label.font = font
            }else {
                changeFont(view: item, font: font)
            }

        }
    }

    open override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        let font = YOUR_FONT
        changeFont(view: self.view, font: font! )
    }
}