如何在Swift（iOS 7）中向UIAlertView添加操作

Question

我想在重试按钮中添加一个动作，但是当用户按下重试按钮时没有任何反应。

var createAccountErrorAlert: UIAlertView = UIAlertView()

createAccountErrorAlert.delegate = self                

createAccountErrorAlert.title = "Oops"
createAccountErrorAlert.message = "Could not create account!"
createAccountErrorAlert.addButtonWithTitle("Dismiss")
createAccountErrorAlert.addButtonWithTitle("Retry")

createAccountErrorAlert.show()

确定按钮索引的功能？

func alertView(View: UIAlertView!, clickedButtonAtIndex buttonIndex: Int){

    switch buttonIndex{

    case 1:
        createAccount()

    default:
        //Some code here..

    }
}

Answer 1

我测试了你的代码，它对我来说很好，它打印相应的结果：

func showAlert(){
    var createAccountErrorAlert: UIAlertView = UIAlertView()

    createAccountErrorAlert.delegate = self

    createAccountErrorAlert.title = "Oops"
    createAccountErrorAlert.message = "Could not create account!"
    createAccountErrorAlert.addButtonWithTitle("Dismiss")
    createAccountErrorAlert.addButtonWithTitle("Retry")

    createAccountErrorAlert.show()
}

func alertView(View: UIAlertView!, clickedButtonAtIndex buttonIndex: Int){

    switch buttonIndex{

    case 1:
        NSLog("Retry");
    break;
    case 0:
        NSLog("Dismiss");
        break;
    default:
        NSLog("Default");
        break;
        //Some code here..

    }
}

当我点击关闭按钮时打印关闭。

Answer 2

那是因为你的重试按钮的索引是1，而不是0. dismiss按钮的索引为0。

如果将以下代码放在操场中，您将实际看到按钮的索引（如addButtonWithTitle方法中所述）：

var createAccountErrorAlert: UIAlertView = UIAlertView()
createAccountErrorAlert.title = "Oops"
createAccountErrorAlert.message = "Could not create account!"
createAccountErrorAlert.addButtonWithTitle("Dismiss") //Prints 0
createAccountErrorAlert.addButtonWithTitle("Retry") //Prints 1

Answer 3

索引错了。 以下（基于iOS单视图默认应用程序模板）适用于我（我连接按钮以触发@IBAction buttonPressed ）。 不要忘记让您的视图控制器成为UIAlertViewDelegate （虽然以下工作没有这样做）：

import UIKit

class ViewController: UIViewController, UIAlertViewDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func buttonPressed(sender : AnyObject) {
        var createAccountErrorAlert: UIAlertView = UIAlertView()

        createAccountErrorAlert.delegate = self

        createAccountErrorAlert.title = "Oops"
        createAccountErrorAlert.message = "Could not create account!"
        createAccountErrorAlert.addButtonWithTitle("Dismiss")
        createAccountErrorAlert.addButtonWithTitle("Retry")

        createAccountErrorAlert.show()
    }

    func alertView(View: UIAlertView!, clickedButtonAtIndex buttonIndex: Int) {

        switch buttonIndex {

        default:
            println("alertView \(buttonIndex) clicked")

        }
    }
}

Answer 4

继续我的方式，使用较短的代码行：

func showAlert(){
    var alert = UIAlertView(title: "Choose", message: "Which_pill", delegate: self, cancelButtonTitle:"Red")
    alert.addButtonWithTitle("Blue")
    alert.show()
}

func alertView(View: UIAlertView!, clickedButtonAtIndex buttonIndex: Int){
    switch buttonIndex{
    case 1: println("Blue")
    case 0: println("Red")
    default: println("Is this part even possible?")
    }
}