在 Swift 中将多个参数传递给 UIAlertAction

Question

我一直在尝试找到一种方法将多个参数传递给UIAlertAction。以下是我的代码。我想将"源"字符串传递给警报的 joinSelected 操作。

我收到这样的错误：

无法将类型"(

("的值转换为预期的参数类型"((UIAlertAction(->

fileprivate func showBetaAlert(source: String)  {
let betaAlert =  UIAlertController.betaProgramAlert()
let joinAction = UIAlertAction(title: "Join", style: UIAlertActionStyle.default, handler: joinSelected(alert: <#UIAlertAction#>, source: source))
let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.cancel, handler: cancelSelected)
betaAlert.addAction(cancelAction)
betaAlert.addAction(joinAction)
present(betaAlert, animated: true, completion: nil)
}
fileprivate func joinSelected(alert: UIAlertAction, source: String) {
let betaAlert = UIAlertController.signUpAlert()
let cancelAction = UIAlertAction(title: "Cancel", style: .cancel, handler: dismissEmailAction)
let submitAction = UIAlertAction(title: "Submit", style: .default , handler: { [weak self] _ in
guard let stelf = self else { return }
let email = betaAlert.textFields![0] as UITextField
stelf.submitAction(email: email.text!)
})
betaAlert.addAction(cancelAction)
betaAlert.addAction(submitAction)
present(betaAlert, animated: true, completion: nil)
}

Answer 1

替换此行：

let joinAction = UIAlertAction(title: "Join", style: UIAlertActionStyle.default, handler: joinSelected(alert: <#UIAlertAction#>, source: source))

跟：

let joinAction = UIAlertAction(title: "Join", style: UIAlertActionStyle.default, handler: { [weak self] _ in
joinSelected(source: source)
})

并将joinSelected更新为：

fileprivate func joinSelected(source: String) {