View Will Appear 未开火

Question

我正在使用 Swift 2 和 Xcode 7。今天早上，我的应用程序运行良好。然而，并非如此。在我的 viewDidLoad 方法中，我 print("viewdidload")。在我的 viewDidAppear 方法中，我 print("viewdidappear)。 Viewdidload 会打印到日志中，但 viewdidappear 不会。我的应用程序卡在启动屏幕上。这是我的完整代码：

//
//  ViewController.swift
//  Math Practice
//
//  Created by Pranav Wadhwa on 8/7/15.
//  Copyright (c) 2015 Pranav Wadhwa. All rights reserved.
//

import UIKit
import iAd
class ViewController: UIViewController, ADBannerViewDelegate {
@IBOutlet var iAdBannerView: ADBannerView?

func bannerViewDidLoadAd(banner: ADBannerView!) {
    self.iAdBannerView?.hidden = false
}

@IBOutlet var startStop: UIButton!
func bannerViewActionShouldBegin(banner: ADBannerView!, willLeaveApplication willLeave: Bool) -> Bool {
    seconds = 0
    minutes = 0
    correct = 0
    startStop.setTitle("Start", forState: .Normal)
    total = 0
    correctLabel.text = "0/0"
    timerLabel.text = "00:00"
    questionLabel.text = ""
    button1.setTitle("", forState: .Normal)
    button2.setTitle("", forState: .Normal)
    button3.setTitle("", forState: .Normal)
    button4.setTitle("", forState: .Normal)
    timer.invalidate()
    already = false
    return true
}
func bannerView(banner: ADBannerView!, didFailToReceiveAdWithError error: NSError!) {
    self.iAdBannerView?.hidden = true
}
var firstNumber = Int()
var secondNumber = Int()
var sign = String()
var arrayOfSigns = ["add", "subtract", "divide", "multiply"]
var correctAnswer = Int()
var buttonWithCorrectAnswer = Int()
var correct = Int()
var total = Int()
@IBOutlet var timerLabel: UILabel!

@IBOutlet var questionLabel: UILabel!

@IBOutlet var correctLabel: UILabel!

@IBOutlet var button1: UIButton!
@IBOutlet var button2: UIButton!
@IBOutlet var button3: UIButton!
@IBOutlet var button4: UIButton!

var timer = NSTimer()

func updateTime() {
    seconds += 01
    if seconds == 60 {
        minutes++
        seconds = 0
    }
    if seconds < 10 {
        timerLabel.text = "\(minutes):0\(seconds)"
    } else {
        timerLabel.text = "\(minutes):\(seconds)"
    }
}
@IBAction func start(sender: AnyObject) {
    if already == false {
        createQuestion()
        startStop.setTitle("Pause", forState: .Normal)
        already = true
        timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: Selector("updateTime"), userInfo: nil, repeats: true)
        userLevel.text = ""
        userImage.hidden = true
    } else {
        userImage.hidden = false
        startStop.setTitle("Start", forState: .Normal)
        questionLabel.text = ""
        button1.setTitle("", forState: .Normal)
        button2.setTitle("", forState: .Normal)
        button3.setTitle("", forState: .Normal)
        button4.setTitle("", forState: .Normal)
        timer.invalidate()
        already = false
    }
}

@IBAction func reset(sender: AnyObject) {
    if NSUserDefaults.standardUserDefaults().objectForKey("correctQuestions") != nil {
        totalCorrectQuestions = NSUserDefaults.standardUserDefaults().objectForKey("correctQuestions") as! Int
    }

    userLevel.text = "Level " + String(usersLevel)
    userImage.hidden = false
    seconds = 0
    minutes = 0
    correct = 0
    total = 0
    correctLabel.text = "0/0"
    timerLabel.text = "00:00"
    questionLabel.text = ""
    button1.setTitle("", forState: .Normal)
    button2.setTitle("", forState: .Normal)
    button3.setTitle("", forState: .Normal)
    button4.setTitle("", forState: .Normal)
    timer.invalidate()
    already = false

}

var seconds = 0
var minutes = 0
var already = false


@IBAction func button1(sender: AnyObject) {
    if buttonWithCorrectAnswer == 1 {
        correct += 1
    }
    total += 1
    createQuestion()
}
@IBAction func button2(sender: AnyObject) {
    if buttonWithCorrectAnswer == 2 {
        correct += 1
    }
    total += 1
    createQuestion()
}
@IBAction func button3(sender: AnyObject) {
    if buttonWithCorrectAnswer == 3 {
        correct += 1
    }
    total += 1
    createQuestion()
}
@IBAction func button4(sender: AnyObject) {
    if buttonWithCorrectAnswer == 4 {
        correct += 1
    }

    total += 1
    createQuestion()
}

func createQuestion() {
    correctLabel.text = "\(correct)/\(total)"

    firstNumber = Int(arc4random_uniform(39))
    secondNumber = Int(arc4random_uniform(39))
    firstNumber -= 20
    secondNumber -= 20
    let i = Int(arc4random_uniform(4))
    sign = arrayOfSigns[i]
    if sign == "divide" {
        firstNumber = Int(arc4random_uniform(39))
        secondNumber = Int(arc4random_uniform(39))
        firstNumber -= 20
        secondNumber -= 20
    }

    if sign == "add" {
        questionLabel.text = "\(firstNumber) + \(secondNumber)"
        correctAnswer = firstNumber + secondNumber
    }
    if sign == "subtract" {
        questionLabel.text = "\(firstNumber) - \(secondNumber)"
        correctAnswer = firstNumber - secondNumber
    }
    if sign == "divide" {
        firstNumber = firstNumber * secondNumber
        questionLabel.text = "\(firstNumber) / \(secondNumber)"
        correctAnswer = firstNumber / secondNumber
    }
    if sign == "multiply" {
        questionLabel.text = "\(firstNumber) * \(secondNumber)"
        correctAnswer = firstNumber * secondNumber
    }
    createAnswers()
}
var firstRandomAnswer = Int()
var secondRandomAnswer = Int()
var thirdRandomAnswer = Int()
var fourthRandomAnswer = Int()

func createAnswers() {
    buttonWithCorrectAnswer = Int(arc4random_uniform(4) + 1)

    //Insert Correct Answer
    if buttonWithCorrectAnswer == 1 {
        button1.setTitle("\(correctAnswer)", forState: .Normal)
    } else if buttonWithCorrectAnswer == 2 {
        button2.setTitle("\(correctAnswer)", forState: .Normal)
    } else if buttonWithCorrectAnswer == 3 {
        button3.setTitle("\(correctAnswer)", forState: .Normal)
    } else if buttonWithCorrectAnswer == 4 {
        button4.setTitle("\(correctAnswer)", forState: .Normal)
    }

    //Setup Fake Answer
    if sign == "add" || sign == "subtract" || sign == "divide" {

        firstRandomAnswer = Int(arc4random_uniform(79))
        firstRandomAnswer -= 40

        secondRandomAnswer = Int(arc4random_uniform(79))
        secondRandomAnswer -= 40
        while secondRandomAnswer == firstRandomAnswer {
            secondRandomAnswer = Int(arc4random_uniform(79))
            secondRandomAnswer -= 40
        }
        thirdRandomAnswer = Int(arc4random_uniform(79))
        thirdRandomAnswer -= 40
        while thirdRandomAnswer == secondRandomAnswer || thirdRandomAnswer == firstRandomAnswer {
            thirdRandomAnswer = Int(arc4random_uniform(79))
            thirdRandomAnswer -= 40
        }

        fourthRandomAnswer = Int(arc4random_uniform(79))
        fourthRandomAnswer -= 40
        while fourthRandomAnswer == thirdRandomAnswer || fourthRandomAnswer == secondRandomAnswer || fourthRandomAnswer == firstRandomAnswer {
            fourthRandomAnswer = Int(arc4random_uniform(79))
            fourthRandomAnswer -= 40
        }
    }
    if sign == "multiply" {

        firstRandomAnswer = Int(arc4random_uniform(799))
        firstRandomAnswer -= 400

        secondRandomAnswer = Int(arc4random_uniform(799))
        secondRandomAnswer -= 400
        while secondRandomAnswer == firstRandomAnswer {
            secondRandomAnswer = Int(arc4random_uniform(799))
            secondRandomAnswer -= 400
        }

        thirdRandomAnswer = Int(arc4random_uniform(799))
        thirdRandomAnswer -= 400
        while thirdRandomAnswer == secondRandomAnswer || thirdRandomAnswer == firstRandomAnswer {
            thirdRandomAnswer = Int(arc4random_uniform(799))
            thirdRandomAnswer -= 400
        }

        fourthRandomAnswer = Int(arc4random_uniform(799))
        fourthRandomAnswer -= 400
        while fourthRandomAnswer == thirdRandomAnswer || fourthRandomAnswer == secondRandomAnswer || fourthRandomAnswer == firstRandomAnswer {
            fourthRandomAnswer = Int(arc4random_uniform(799))
            fourthRandomAnswer -= 400
        }
    }


    //Insert Fake Answers
    if buttonWithCorrectAnswer != 1 {
        button1.setTitle("\(firstRandomAnswer)", forState: .Normal)
    }
    if buttonWithCorrectAnswer != 2 {
        button2.setTitle("\(secondRandomAnswer)", forState: .Normal)
    }
    if buttonWithCorrectAnswer != 3 {
        button3.setTitle("\(thirdRandomAnswer)", forState: .Normal)
    }
    if buttonWithCorrectAnswer != 4 {
        button4.setTitle("\(fourthRandomAnswer)", forState: .Normal)
    }
}

@IBOutlet var backgroundImage: UIImageView!
override func viewDidLoad() {
    super.viewDidLoad()
    super.viewDidAppear(false)
    print("viewdidload")

    correctLabel.text = "0/0"
    timerLabel.text = "00:00"
    self.canDisplayBannerAds = true
    self.iAdBannerView?.delegate = self
    self.iAdBannerView?.hidden = true
    var image = arc4random_uniform(2)
    image++
    userImage.hidden = false
    backgroundImage.image = UIImage(named: "background_" + String(image))
    if NSUserDefaults.standardUserDefaults().objectForKey("correctQuestions") != nil {
        totalCorrectQuestions = NSUserDefaults.standardUserDefaults().objectForKey("correctQuestions") as! Int
    }
    totalCorrectQuestions += correct
    NSUserDefaults.standardUserDefaults().setObject(totalCorrectQuestions, forKey: "correctQuestions")
    if NSUserDefaults.standardUserDefaults().objectForKey("userLevel") != nil {
        usersLevel = NSUserDefaults.standardUserDefaults().objectForKey("userLevel") as! Int
    }
    NSUserDefaults.standardUserDefaults().setObject(usersLevel, forKey: "userLevel")
    userLevel.text = "Level " + String(usersLevel)
    pointsForUpgrade = usersLevel * 10


    for var i = 1; i > 0; i++ {
        totalCorrectQuestions += correct
        NSUserDefaults.standardUserDefaults().setObject(totalCorrectQuestions, forKey: "correctQuestions")
        if NSUserDefaults.standardUserDefaults().objectForKey("userLevel") != nil {
            usersLevel = NSUserDefaults.standardUserDefaults().objectForKey("userLevel") as! Int
        }
        if totalCorrectQuestions >= pointsForUpgrade {
            usersLevel++
            pointsForUpgrade = usersLevel * 10
        }
        NSUserDefaults.standardUserDefaults().setObject(usersLevel, forKey: "userLevel")
    }
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}
var pointsForUpgrade = Int()

@IBOutlet var userImage: UIImageView!
var totalCorrectQuestions = Int()
var usersLevel = 1

@IBOutlet var userLevel: UILabel! 
}

我哪里出错了？

Answer 1

代码不工作的原因是因为我试图在 viewDidLoad 方法中设置一个循环以使其永远工作。我需要删除它。

View Will Appear 未开火

View Will Appear not firing

viewdidload

viewdidappear

ios

xcode7

swift2