ios - 在具有委托(delegate)的多个 UIViewController 队列上使用解雇 View Controller

Question

当我的应用程序第一次启动时，我将展示 4 UIViewController 的教程。每个 UIViewController 都有一个带有显示下一个 ViewController 的 segue 的 Button。最后一个 ViewController 有一个“让我们开始”按钮，它应该完全关闭教程。

问题:这将关闭除第一个之外的所有 ViewController。我不明白为什么？!

我的期望:

在最后一个ViewController4上，我调用第一个ViewController的dismissIntroduction()函数，所以除了所有ViewController(包括ViewController1)之外的所有ViewController都应该消失。当我在第一个 ViewController 上放置一个按钮并调用函数“dismissIntroduction()”时，它就会消失。

ViewController 1(WelcomeViewController):

protocol WelcomeViewDelegate {
    func dismissIntroduction()
}

class WelcomeViewController: UIViewController, WelcomeViewDelegate {

    override func viewDidLoad() {
        super.viewDidLoad()

        // Do any additional setup after loading the view.
    }

    func dismissIntroduction() {
        self.dismissViewControllerAnimated(true, completion: nil)
    }


    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        let destination = segue.destinationViewController as! ViewController2
        destination.delegate = self
    }

}

ViewController 2:

class ViewController2: UIViewController {

    var delegate:WelcomeViewDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
    }        

    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        let destination = segue.destinationViewController as! ViewController3
        destination.delegate = self.delegate
    }

}

ViewController 3:

class ViewController3: UIViewController {

    var delegate:WelcomeViewDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
    }        

    // MARK: - Navigation

    // In a storyboard-based application, you will often want to do a little preparation before navigation
    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        let destination = segue.destinationViewController as! ViewController4
        destination.delegate = self.delegate
    }

}

ViewController4(最后一个):

class ViewController4: UIViewController {

    var delegate:WelcomeViewDelegate?

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func pressLetsStart(sender: AnyObject) {
        self.delegate!.dismissIntroduction()
    }

}

编辑:当我两次放置missViewControllerAnimated函数时，我得到了它的工作!？

func dismissIntroduction() {
    self.dismissViewControllerAnimated(true, completion: nil)
    self.dismissViewControllerAnimated(true, completion: nil)
}

但是为什么呢？我不明白背后的逻辑...

Answer 1

您正在寻找错误的问题解决方案，您需要做的是寻找 Unwind Segues。完成本教程:https://spin.atomicobject.com/2014/10/25/ios-unwind-segues/