Swift警告框带有“确定”和“取消”按钮：哪个按钮被点击了？

Question

我在Xcode中用Swift编写了一个警告窗口，我想确定用户选择了哪个按钮（这是一个确认对话框），以便执行某些操作或不执行任何操作。

目前我的代码如下：

@IBAction func pushedRefresh(sender: AnyObject) {
    var refreshAlert = UIAlertView()
    refreshAlert.title = "Refresh?"
    refreshAlert.message = "All data will be lost."
    refreshAlert.addButtonWithTitle("Cancel")
    refreshAlert.addButtonWithTitle("OK")
    refreshAlert.show()
}

我可能在错误地使用这些按钮，请指正，因为这对我来说都是新的东西。

- B_s

---

将操作添加到UIAlertview按钮的方法（使用Swift iOS） - Mixaz

Answer 1

如果您正在使用iOS8及以上版本，应该使用UIAlertController，UIAlertView已经过时。

以下是如何使用它的示例：

var refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertControllerStyle.Alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .Default, handler: { (action: UIAlertAction!) in
  print("Handle Ok logic here")
  }))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: { (action: UIAlertAction!) in
  print("Handle Cancel Logic here")
  }))

presentViewController(refreshAlert, animated: true, completion: nil)

正如您所看到的，UIAlertAction 的块处理程序处理按钮按下事件。这里有一个很棒的教程（尽管该教程不是使用 Swift 编写的）：http://hayageek.com/uialertcontroller-example-ios/

Swift 3 更新：

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertControllerStyle.alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
    print("Handle Ok logic here")
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
    print("Handle Cancel Logic here")
}))

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

Swift 5更新：

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertControllerStyle.alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
      print("Handle Ok logic here")
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
      print("Handle Cancel Logic here")
}))

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

Swift 5.3 更新：

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertController.Style.alert)

refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
      print("Handle Ok logic here")
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
      print("Handle Cancel Logic here")
}))

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

- Michael Wildermuth

---

在你的示例中，可以使用 UIAlertActionStyle.Cancel 而不是 .Default。 - Tristan Warner-Smith

如果我想在取消操作中什么都不做，我可以返回空吗？ - Gabriel Rodrigues

当然，从技术上讲，在这个例子中我只是在记录日志。但是如果我移除了日志，那么我将什么都不做。 - Michael Wildermuth

当答案针对较新版本的Swift进行更新时，这非常棒。 - BlackTigerX

有人知道如何将辅助功能 ID 添加到“确定”和“取消”操作中吗？ - Kamaldeep singh Bhatia

那么Swift 3和Swift 5之间的区别就是在print语句中多了一个制表符吗？xD - joe

Answer 2

var refreshAlert = UIAlertController(title: "Log Out", message: "Are You Sure to Log Out ? ", preferredStyle: UIAlertControllerStyle.Alert)

refreshAlert.addAction(UIAlertAction(title: "Confirm", style: .Default, handler: { (action: UIAlertAction!) in
    self.navigationController?.popToRootViewControllerAnimated(true)
}))

refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .Default, handler: { (action: UIAlertAction!) in

    refreshAlert .dismissViewControllerAnimated(true, completion: nil)


}))

presentViewController(refreshAlert, animated: true, completion: nil)

- Alvin George

---

更新 Swift 5.3： refreshAlert.dismiss(animated: true, completion: nil) - Deepak Ghadi

Answer 3

更新至Swift 3：

// 函数定义：

@IBAction func showAlertDialog(_ sender: UIButton) {
        // Declare Alert
        let dialogMessage = UIAlertController(title: "Confirm", message: "Are you sure you want to Logout?", preferredStyle: .alert)

        // Create OK button with action handler
        let ok = UIAlertAction(title: "OK", style: .default, handler: { (action) -> Void in
             print("Ok button click...")
             self.logoutFun()
        })

        // Create Cancel button with action handlder
        let cancel = UIAlertAction(title: "Cancel", style: .cancel) { (action) -> Void in
            print("Cancel button click...")
        }

        //Add OK and Cancel button to dialog message
        dialogMessage.addAction(ok)
        dialogMessage.addAction(cancel)

        // Present dialog message to user
        self.present(dialogMessage, animated: true, completion: nil)
    }

// logoutFun() 函数定义：

func logoutFun()
{
    print("Logout Successfully...!")
}

- Kiran Jadhav

Answer 4

您可以通过使用UIAlertController轻松实现此操作

let alertController = UIAlertController(
       title: "Your title", message: "Your message", preferredStyle: .alert)
let defaultAction = UIAlertAction(
       title: "Close Alert", style: .default, handler: nil)
//you can add custom actions as well 
alertController.addAction(defaultAction)

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

.

参考资料：iOS显示警报

- Shaba Aafreen

Answer 5

点赞一下：)

步骤1：创建一个新的独立类

import Foundation
import UIKit

        class AppAlert: NSObject {
        
        //Singleton class
        static let shared = AppAlert()
        
        //MARK: - Delegate
        var onTapAction : ((Int)->Void)?
        
        //Simple Alert view
        public func simpleAlert(view: UIViewController, title: String?, message: String?){
            ToastManager.show(title: title ?? "", state: .error)
        }
        
        //Alert view with Single Button
        public func simpleAlert(view: UIViewController, title: String, message: String, buttonTitle: String) {
            
            let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertController.Style.alert)
            //okButton Action
            let okButton = UIAlertAction(title: buttonTitle, style: UIAlertAction.Style.default) {
                (result : UIAlertAction) -> Void in
                self.onTapAction?(0)
            }
            alert.addAction(okButton)
            view.present(alert, animated: true, completion: nil)
        }
        
        //Alert view with Two Buttons
        public func simpleAlert(view: UIViewController, title: String, message: String, buttonOneTitle: String, buttonTwoTitle: String){
            let alert = UIAlertController(title: title, message: message, preferredStyle: UIAlertController.Style.alert)
            
            //Button One Action
            let buttonOne = UIAlertAction(title: buttonOneTitle, style: UIAlertAction.Style.default) {
                (result : UIAlertAction) -> Void in
                self.onTapAction?(0)
            }
            
            //Button Two Action
            let buttonTwo = UIAlertAction(title: buttonTwoTitle, style: UIAlertAction.Style.default) {
                (result : UIAlertAction) -> Void in
                self.onTapAction?(1)
            }
            alert.addAction(buttonOne)
            alert.addAction(buttonTwo)
            view.present(alert, animated: true, completion: nil)
        }
        
    }

第二步：调用As

    AppAlert.shared.simpleAlert(view: self, title: "Register First", message: "Please Register to Proceed", buttonOneTitle: "Cancel", buttonTwoTitle: "OK")
            AppAlert.shared.onTapAction = { [weak self] tag in
                guard let self = self else {
                    return
                }
                if tag == 0 {
                  // DO YOUR WORK  
                } else if tag == 1 {
                 // DO YOUR WORK  
                }
            }

- Asfar Hussain Siddiqui

---

这里的ToastManager是什么？ - Mahmoud Zinji

你可以在这里管理你的业务逻辑。我使用ToastManager类展示了自定义警告提示。 - Asfar Hussain Siddiqui

Answer 6

您可能想考虑使用SCLAlertView，这是一个替代UIAlertView或UIAlertController的选择。

UIAlertController仅适用于iOS 8.x或更高版本，SCLAlertView是支持旧版本的好选择。

github查看详情

示例：

let alertView = SCLAlertView()
alertView.addButton("First Button", target:self, selector:Selector("firstButton"))
alertView.addButton("Second Button") {
    print("Second button tapped")
}
alertView.showSuccess("Button View", subTitle: "This alert view has buttons")

- Soon Khai

Answer 7

Swift 5 的小更新：

let refreshAlert = UIAlertController(title: "Refresh", message: "All data will be lost.", preferredStyle: UIAlertController.Style.alert)

    refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
          print("Handle Ok logic here")
    }))

    refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: { (action: UIAlertAction!) in
          print("Handle Cancel Logic here")
    }))

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

- Marcin Żmigrodzki