ios - 来自扩展的 UIAlertController

Question

我有代码可以测试插入只有数字。

如果我插入字母，如何使用消息进行提醒？

String+onlyNumbers.swift

extension String {
    func onlyNumbers() ->String{
        do{
            let regex = try NSRegularExpression(pattern: "([//.,\\d])*", options:[.dotMatchesLineSeparators])
            var result : String = ""

            for resultMatch in regex.matches(in: self, options: NSRegularExpression.MatchingOptions.init(rawValue: 0), range: NSMakeRange(0, NSString(string: self).length)) {
                result += NSString(string: self).substring(with: resultMatch.range)
            }
            return result
        }
        catch
        {

        }
        return ""
    }
}

ViewControler.swift

let saveAction = UIAlertAction(title: NSLocalizedString("Past",comment: ""), style: .default, handler: {
    (alert: UIAlertAction!) -> Void in
    self.displayResultLabel.text = UIPasteboard.general.string?.onlyNumbers()
    print("Pasted")
})

"""""

let saveAction = UIAlertAction(title: NSLocalizedString("Past",comment: ""), style: .default, handler: {
        (alert: UIAlertAction!) -> Void in
        if UIPasteboard.general.string?.onlyNumbers() == "" {
            let alertController = UIAlertController(title: "Calc Pro", message: UIPasteboard.general.string, preferredStyle: .alert)
            alertController.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))
            self.present(alertController, animated: false, completion: nil)
        } else {
            self.displayResultLabel.text = UIPasteboard.general.string
        }
        print("Pasted")
    })

Answer 1

您可以通过实例化 UIAlertController 来创建警报。您可以使用 onlyNumbers 函数的输出作为警报 Controller 的消息。

然后你需要添加 UIAlertAction(s) 到它最后调用 self.present 来显示来自 UIViewController 子类的警报 Controller .

if UIPasteboard.general.string?.onlyNumbers() == "" {
    let alertController = UIAlertController(title: "Calc Pro", message: UIPasteboard.general.string?, preferredStyle: .alert)
    alertController.addAction(UIAlertAction(title: "Ok", style: .default, handler: nil))
    self.present(alertController, animated: false, completion: nil)
}