ios - 警告 : Attempt to present * on * whose view is not in the window hierarchy - swift

Question

我正在尝试呈现一个 ViewController 如果数据模型中有任何已保存的数据。但是我收到以下错误:

Warning: Attempt to present * on *whose view is not in the window hierarchy"

相关代码:

override func viewDidLoad() {
    super.viewDidLoad()
    loginButton.backgroundColor = UIColor.orangeColor()

    var request = NSFetchRequest(entityName: "UserData")
    request.returnsObjectsAsFaults = false

    var appDel:AppDelegate = (UIApplication.sharedApplication().delegate as AppDelegate)
    var context:NSManagedObjectContext = appDel.managedObjectContext!

    var results:NSArray = context.executeFetchRequest(request, error: nil)!

    if(results.count <= 0){
        print("Inga resultat")
    } else {
        print("SWITCH VIEW PLOX")
        let internVC = self.storyboard?.instantiateViewControllerWithIdentifier("internVC") as internViewController
        self.presentViewController(internVC, animated: true, completion: nil)
    }
}

我尝试过使用 Google 发现的不同解决方案，但均未成功。

Answer 1

此时在您的代码中， View Controller 的 View 仅已创建，但尚未添加到任何 View 层次结构中。如果您想尽快从该 View Controller 中呈现，您应该在 viewDidAppear 中进行，以确保最安全。