Question

如果用户尚未设置应用程序，我正在尝试在应用程序首次启动时运行一段代码。目前，代码通过另一种方法（清洁度）检查存储的UserDefaults，以查看是否已设置应用程序。然而，在这种情况下，这应该无关紧要，因为我硬编码软件认为应用程序尚未设置。然后，我检查应用程序是否已在ViewController的viewDidAppear函数中设置（引用硬代码）。在看到它尚未设置后，它会调用一个方法，要求转到SetupViewController。出于某种原因，它会两次调用segue。因此，一旦执行了segue并且我看到了另一个视图，它似乎尝试再次运行它然后抛出异常。下面是我的代码和我的日志输出。我的代码中有什么不正确，或者我的代码逻辑中缺少什么？我还检查并确保segue在Main.storyboard中有正确的标识符。先谢谢你们！

ViewDidAppear代码：

/*
 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()
    }
}

调用segue的方法称为“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")

}

日志输出：

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

解决方案以一种非常简单的方式出现。我忘了在SetupViewController中创建一个viewDidAppear甚至viewDidLoad函数。这解决了这个问题。

塞格被召唤两次，我不知道为什么 - 斯威夫特

1 个答案: