Segue被叫了兩次，我不確定為什么-Swift

Question

如果用戶尚未安裝應用程序，則我試圖在應用程序首次啟動時運行代碼塊。 當前，該代碼通過另一種方法（出於清潔目的）檢查存儲的UserDefaults，以查看是否已安裝該應用程序。 但是，在這種情況下這無關緊要，因為我對軟件進行了硬編碼，以為尚未安裝該應用程序。 然后，我讓應用程序檢查以查看是否已在ViewController的viewDidAppear函數中設置了該程序（參考硬代碼）。 看到尚未設置后，它便調用一個方法，要求將其隔離到SetupViewController。 但是由於某種原因，它兩次調用segue。 因此，一旦執行了segue並看到了另一個視圖，它似乎會嘗試再次運行它，然后引發異常。 以下是我的代碼和日志的輸出。 我的代碼中什么是不正確的，或者我的代碼邏輯中缺少什么？ 我還檢查並確保segue在Main.storyboard中確實具有正確的標識符。 在此先感謝大家！

ViewDidAppear代碼：

/*
 ViewDidAppear - If the view has appeared after loading we will run some code to check the state of the app.
 */
override func viewDidAppear(_ animated: Bool) {
    // If the application hasn't been setup and it believes it isn't setup run setup.
    if(checkIfSetup() != true && hasSetup == false)
    {
        print("attempted run")
        runSetup()
    }
        // If the application has been setup and believes it has been setup, load view.
    else if(checkIfSetup() == true && hasSetup == true)
    {
        loadApp()
    }
}

調用segue的方法稱為“ RunSetup：”

/*
 RunSetup - Runs the setup for the application environment.
 */
func runSetup()
{
    print("Running setup for AppName") // Notify the log that you are running the App's setup.

    // ## Start by clearing all possibly stored data. ##

    //REALM - Destroy Database if it exists

    try! realm.write {
        realm.deleteAll()
    }

    //Begin setting up the environment
    self.performSegue(withIdentifier: "dismissAndCreate", sender: self)
    print("tryingSegue")

}

日志輸出：

attempted run Running setup for AppName tryingSegue attempted run Running setup for AppName 2017-04-03 17:12:57.404 AppName[22109:3226052] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Receiver (<AppName.SetupAppViewController: 0x7ffc97824400>) has no segue with identifier 'dismissAndCreate'' *First Throw Stack is then listed*

Answer 1

解決方案非常簡單。 我忘了在SetupViewController中創建一個viewDidAppear甚至viewDidLoad函數。 這樣就解決了問題。