Question

我已经查看了StackOverFlow。没有现成的问题似乎对我有帮助。

我正在使用ParseUI来处理用户登录功能，但在签署新用户时遇到了问题。

问题：当用户注册并点击“注册”按钮时，会出现此错误并且不会发生任何错误：

<Warning: Attempt to present edus.ClassEntryViewController: 0x7f8800ceb0a0> on <PFLogInViewController: 0x7f8800c2f520> whose view is not in the window hierarchy!

我不知道如何解决这个问题。相关代码如下：

import UIKit
import Parse
import Bolts
import ParseUI
import FBSDKCoreKit
import ParseFacebookUtils


@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

var window: UIWindow?
var parseLoginHelper: ParseLoginHelper!

override init() {
    super.init()

    parseLoginHelper = ParseLoginHelper {[unowned self] user, error in
        // Initialize the ParseLoginHelper with a callback
        if let error = error {
            // 1
            ErrorHandling.defaultErrorHandler(error)
        } else  if let user = user {
            let storyboard = UIStoryboard(name: "Main", bundle: nil)
            //creation
            let classNavEntry = storyboard.instantiateViewControllerWithIdentifier("ClassNavEntry") as! UIViewController
            //presentation. PROBLEM HERE??
            self.window?.rootViewController!.presentViewController(classNavEntry, animated:true, completion:nil)
        }
    }
}

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {
let user = PFUser.currentUser()

    let startViewController: UIViewController;

    if (user != nil) {
        // 3
        // if we have a user, set the ClassNavEntry to be the initial View Controller
        let storyboard = UIStoryboard(name: "Main", bundle: nil)
        //problem may arise here
        startViewController =
                storyboard.instantiateViewControllerWithIdentifier("ClassNavEntry") as! UINavigationController
    } else {
        // 4
        // Otherwise set the LoginViewController to be the first
        let loginViewController = PFLogInViewController()
        loginViewController.fields = .UsernameAndPassword | .LogInButton | .SignUpButton | .PasswordForgotten | .Facebook
        loginViewController.delegate = parseLoginHelper
        loginViewController.signUpController?.delegate = parseLoginHelper
        startViewController = loginViewController
    }

    // 5
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    self.window?.rootViewController = startViewController;
    self.window?.makeKeyAndVisible()

更新：我知道导致问题的原因，仍在弄清楚如何解决问题。

问题是有两个视图控制器：loginViewController和SignupViewController。我在这里指定了根视图控制器是loginViewController：

loginViewController.delegate = parseLoginHelper
        loginViewController.signUpController?.delegate = parseLoginHelper
        startViewController = loginViewController
    }

    // 5
    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    //THIS SPECIFIES ROOTVIEW TO BE LOGINVIEWCONTROLLER
    self.window?.rootViewController = startViewController
    self.window?.makeKeyAndVisible()

所以我需要能够在SignUpViewController上调用parseHelper ......

Answer 1

在ErrorHandling.defaultErrorHandler（错误）中你调用windows [0]吗？这应该是问题。

您正尝试在不是当前显示窗口的窗口上显示视图控制器（错误）。

一种解决方案可能是将窗口作为参数传递给ErrorHandling函数。

在PFLogInViewController上显示* .viewController，其视图不在窗口层次结构中

1 个答案: