ios - swift/Xcode 中的 UIAlertView

Question

我有一个关于 swift 中的 UIAlertview 的问题。我有一个警报 View ，允许用户在“教师”和“学生”两个选项之间进行选择，并根据单击的按钮将用户带到新屏幕。它工作正常，唯一的问题是我在每个新屏幕上都有一个后退按钮，如果用户单击了错误的按钮，该按钮会将用户带回到上一个屏幕。这就是问题发生的地方。如果用户在 naviagting 返回页面后单击触发 alertview 的按钮，则 alertivew 会记住用户上次单击的按钮并执行以此为基础。抱歉，如果这令人困惑，我希望他们每次都能在选项之间进行选择，并且让 alertview 不根据他们之前的选择执行。抱歉，如果这令人困惑，非常感谢所有帮助。

这是我目前的代码

@IBAction func needToRegisterClicked(sender: AnyObject) {

    let alertController = UIAlertController(title: "Please choose", message: "Teacher or Student?", preferredStyle: UIAlertControllerStyle.Alert)

    alertController.view.tintColor = UIColor.blackColor()

    alertController.addAction(UIAlertAction(title: "Teacher", style: .Default, handler: { (action) in

        print("Teacher Chosen")



        let ac = UIAlertController(title: "Enter Access Code", message: nil, preferredStyle: .Alert)
        ac.addTextFieldWithConfigurationHandler { (textField: UITextField!) in
            textField.keyboardType = UIKeyboardType.NumberPad }



        ac.view.tintColor = UIColor.blackColor()

        let submitAction = UIAlertAction(title: "Submit", style: .Default) { [unowned self, ac] (action: UIAlertAction!) in
            let answer = ac.textFields![0] as! UITextField
            if answer.text == "3280464" {

                self.performSegueWithIdentifier("School Register", sender: nil)

            } else {

                let alert2 = UIAlertController(title: "Sorry!", message: "Incorrect access code", preferredStyle: UIAlertControllerStyle.Alert)
                self.presentViewController(alert2, animated: true, completion: nil)

                alert2.addAction(UIAlertAction(title: "Dismiss", style: .Default, handler: nil))


            }
            // do something interesting with "answer" here
        }

        ac.addAction(submitAction)

        self.presentViewController(ac, animated: true, completion: nil)






    }))

    alertController.addAction(UIAlertAction(title: "Student", style: .Default, handler: { (action) in

        print("Student Chosen")

        self.performSegueWithIdentifier("Student", sender: nil)


    }))
    self.dismissViewControllerAnimated(true, completion: nil)

    self.presentViewController(alertController, animated: true, completion: nil)





}

编辑:每次按下按钮时，我究竟如何实例化一个新的alertView？抱歉，如果问这个问题很愚蠢，我对整个事情非常陌生。

编辑:我尝试了所有建议的选项，但没有成功，但我现在能够自己解决。我所需要做的就是从末尾删除 self.dismissViewControllerAnimated(true,completion: nil) 。感谢所有回复的人，我真诚地感谢您抽出时间。

Answer 1

我认为如果用户在警报 Controller 中按下了不正确的操作，您想要的是返回到第一个 ViewController，所以我所做的是:- 我添加了“学生”按钮，其代码与教师按钮相同- 我创建了一个存储 bool 值的var，如果true是老师，否则是学生，当你选择你是老师时，var存储一个true值，否则，如果按下学生按钮，它存储false，然后转到下一个ViewController- 在第二个 ViewController 中我创建了一个按钮(后退)

self.performSegueWithIdentifier("backToFirst", 发件人: self)

FirstViewController

import UIKit

var isTeacher: bool !

ViewController 类:UIViewController {

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

@IBAction func needToRegisterClicked(sender: AnyObject) {

    let alertController = UIAlertController(title: "Please choose", message: "Teacher or Student?", preferredStyle: UIAlertControllerStyle.Alert)

    alertController.view.tintColor = UIColor.blackColor()

    //Button teacher

    alertController.addAction(UIAlertAction(title: "Teacher", style: .Default, handler: { (action) in

        print("Teacher Chosen")

        isTeacher = true

        let ac = UIAlertController(title: "Enter Access Code", message: nil, preferredStyle: .Alert)
        ac.addTextFieldWithConfigurationHandler { (textField: UITextField!) in
            textField.keyboardType = UIKeyboardType.NumberPad }



        ac.view.tintColor = UIColor.blackColor()

        let submitAction = UIAlertAction(title: "Submit", style: .Default) { [unowned self, ac] (action: UIAlertAction!) in
            let answer = ac.textFields![0] as! UITextField
            if answer.text == "3280464" {

                self.performSegueWithIdentifier("School Register", sender: self)

            } else {

                let alert2 = UIAlertController(title: "Sorry!", message: "Incorrect access code", preferredStyle: UIAlertControllerStyle.Alert)
                self.presentViewController(alert2, animated: true, completion: nil)

                alert2.addAction(UIAlertAction(title: "Dismiss", style: .Default, handler: nil))


            }
            // do something interesting with "answer" here
        }

        ac.addAction(submitAction)

        self.presentViewController(ac, animated: true, completion: nil)

        }
        //Ends Button Teacher

        )


    )

    //Button Student

    alertController.addAction(UIAlertAction(title: "Student", style: .Default, handler: { (action) in

        print("Student Chosen")

        isTeacher = false

        let ac = UIAlertController(title: "Enter Access Code", message: nil, preferredStyle: .Alert)
        ac.addTextFieldWithConfigurationHandler { (textField: UITextField!) in
            textField.keyboardType = UIKeyboardType.NumberPad }



        ac.view.tintColor = UIColor.blackColor()

        let submitAction = UIAlertAction(title: "Submit", style: .Default) { [unowned self, ac] (action: UIAlertAction!) in
            let answer = ac.textFields![0] as! UITextField
            if answer.text == "3280464" {

                self.performSegueWithIdentifier("School Register", sender: self)

            } else {

                let alert2 = UIAlertController(title: "Sorry!", message: "Incorrect access code", preferredStyle: UIAlertControllerStyle.Alert)
                self.presentViewController(alert2, animated: true, completion: nil)

                alert2.addAction(UIAlertAction(title: "Dismiss", style: .Default, handler: nil))


            }
            // do something interesting with "answer" here
        }

        ac.addAction(submitAction)

        self.presentViewController(ac, animated: true, completion: nil)

        }


        )


    )

    //Ends Button Student

    self.presentViewController(alertController, animated: true, completion: nil)
}

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

}

SecondViewController

import UIKit

记录的类:ViewController{

@IBAction func Back(sender: AnyObject) {

    self.performSegueWithIdentifier("backToFirst", sender: self)

}

@IBOutlet weak var navBar: UINavigationBar!

override func viewDidLoad() {
    super.viewDidLoad()

    if(isTeacher == true){

        navBar.topItem?.title = "Teacher Area"

    }else{

        navBar.topItem?.title = "Student Area"

    }



}

}

希望对你有帮助