对< UINavigationController:0x7fd61043fce0>的Swift不平衡调用以开始/结束外观转换 [英] Swift Unbalanced calls to begin/end appearance transitions for <UINavigationController: 0x7fd61043fce0>

问题描述

早上好，我是新来的人，希望这个问题不要太愚蠢.

Good day, I'm new around here, hope this question isn't too silly.

我在运行时收到警告Unbalanced calls to begin/end appearance transitions for <UINavigationController: 0x7fd61043fce0>.但是，我在代码中找不到UINavigationController的任何地方，也找不到项目中的任何其他文件.

I got the warning Unbalanced calls to begin/end appearance transitions for <UINavigationController: 0x7fd61043fce0> during runtime. However, I cannot find anywhere in my code that has UINavigationController, nor any other file in the project.

import UIKit
class ViewController: UIViewController,PFLogInViewControllerDelegate, PFSignUpViewControllerDelegate, FBLoginViewDelegate {

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

    //self.navigationController?.navigationBarHidden = true

    if(PFUser.currentUser() == nil){


        var logInViewController = PFLogInViewController()
        logInViewController.delegate = self

        //customize logInViewController
        logInViewController.fields = PFLogInFields.UsernameAndPassword | PFLogInFields.LogInButton | PFLogInFields.PasswordForgotten | PFLogInFields.Facebook | PFLogInFields.SignUpButton

        logInViewController.facebookPermissions = ["public_profile", "email", "user_friends"]

        logInViewController.logInView.logo  = UIImageView(image: UIImage(named: "Logo"))

        //create a signUpViewController instance
        var signUpViewController = PFSignUpViewController()
        signUpViewController.delegate = self

        //add signUpViewController instance to logInViewController for signUp module.
        logInViewController.signUpController = signUpViewController

        self.parentViewController?.presentViewController(logInViewController, animated: true, completion: nil)

    }else{
        FBSession.activeSession().close()
    }

}

我缺少我应该检查的东西吗?

Am I missing something that I should check?

推荐答案

我将登录的显示方式从viewDidLoad移到viewWillAppear.这样可以确保在显示其他控制器之前，所有设置都已在当前控制器中设置.

I would move the presentation of the login to viewWillAppear from viewDidLoad. This will make sure everything is setup in the current controller before you show another.

还提供来自self而不是self.parentViewController的登录控制器.这可能是您的错误出处.

Also present the login controller from self and not self.parentViewController. This could be where your error comes from.

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