ios - swift 等待用户响应

我创建了一个警报:

var a = 0 // default
let userAction = UIAlertController(title: "Select", message: "Select an action", preferredStyle: UIAlertControllerStyle.alert)

userAction.addAction(UIAlertAction(title: "action 1", style: .default, handler: { (action: UIAlertAction!) in
    a = 1
}))

userAction.addAction(UIAlertAction(title: "action 2", style: .cancel, handler: { (action: UIAlertAction!) in
    a = 2
}))

present(userAction, animated: true, completion: nil)

let resp = Just.get("http://localhost/\(a)").text
return resp

在此代码之后，我正在发送带有参数(a)的请求，但是在选择操作之前发送了请求。
我要如何等待用户选择警报并采取行动？

最佳答案

在类顶部声明typealias

import UIKit
typealias Request = ((_ value:String) -> ())

那么你的方法:-

func showPopup( completion:@escaping Request)  {

    var a = 0 // default
    let userAction = UIAlertController(title: "Select", message: "Select an action", preferredStyle: UIAlertControllerStyle.alert)

    userAction.addAction(UIAlertAction(title: "action 1", style: .default, handler: { (action: UIAlertAction!) in
        a = 1
        let resp = Just.get("http://localhost/\(a)").text
        completion(resp)
    }))

    userAction.addAction(UIAlertAction(title: "action 2", style: .cancel, handler: { (action: UIAlertAction!) in
        a = 2
        let resp =  Just.get("http://localhost/\(a)").text
        completion(resp)
    }))

    self.present(userAction, animated: true, completion: nil)

}

并在需要的地方调用方法:

self.showPopup{ (value) in

     print(value)
}