I created 12 UIButtons by storyboard, in my program, these buttons represent cards,I want to random the buttons' position for shuffling the cards.please do me a favor, give a way or idea to achieve it.
my buttons problem
import UIKit
class ViewController: UIViewController {
lazy var game = Concentration(numberOfPairsOfCards: numberOfPairOfCards) //引入model Concentration
var numberOfPairOfCards : Int {
return (cardButtons.count + 1) / 2 //read only computed properties可以省略get{}
}
var flipCount = 0 {
didSet {
flipsCountLabel.text = "Flips: \(flipCount)"
}
}
#IBOutlet var cardButtons: [UIButton]!
#IBOutlet weak var flipsCountLabel: UILabel!
#IBAction func touchCard(_ sender: UIButton) {
flipCount += 1
if let cardNumber = cardButtons.index(of: sender) {
game.chooseCard(at: cardNumber)
updateViewFromModel()
} else {
print("somthing wrong")
}
}
I have done the job.
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var buttons = [UIButton]()
for index in cardButtons.indices {
buttons.append(cardButtons[index])
}
for index in cardButtons.indices {
cardButtons[index] = buttons.remove(at: buttons.count.arc4random)
}
}
You could add the buttons to an array, shuffle the array and then loop through it and place the buttons. A better solution would be to create a UICollectionView instead though.
Related
I couldn't figure out how to copy value of variable into another variable in Swift, an example code for this in python would be
def assignVariable():
x=1
y=x
return y
RESULT 1
When I did this it doesn't seem to work in Swift. Is there any solution to this or am I doing something wrong?
Edit: problem is at
var originalCount=countDown
it gave me Use of unresolved identifier 'countDown' but when I assign it literally it works. Here's my swift code
import Cocoa
class MainWindow: NSWindowController {
var hitCount = 0
var started:Bool = false
var timer = 10
var colorList: [NSColor] = [ NSColor.black,NSColor.blue,NSColor.brown,NSColor.cyan,NSColor.darkGray,NSColor.gray,NSColor.green,NSColor.lightGray,NSColor.magenta,NSColor.orange,NSColor.purple,NSColor.red,NSColor.white,NSColor.yellow]
#IBOutlet weak var button1: NSButton!
#IBOutlet weak var scrubber1: NSScrubber!
#IBOutlet weak var display: NSTextField!
override func windowDidLoad() {
super.windowDidLoad()
// Implement this method to handle any initialization after your window controller's window has been loaded from its nib file.
}
var countdown=10
var originalCount=countDown
//(countdown,originalCount) = (10,10) //it works if i use this instead
func startGame(){
if(countDown>0 || started==true){
display.stringValue=String(countDown)
countDown-=1
let seconds = 1.0
DispatchQueue.main.asyncAfter(deadline: .now() + seconds) {
self.startGame()
}
}else{
display.stringValue="Done "+String(hitCount)+" Taps in " + String(originalCount) + "Tap to RESET"
started=false
countDown=10;
}
}
#IBAction func labelPress(_ sender: Any) {
display.stringValue="__RESET__"
hitCount=0
countDown=10
started=false
}
#IBAction func buttonPressed(_ sender: Any) {
if started==false{
startGame()
}
button1.bezelColor = colorList[Int.random(in: 0..<colorList.count)]
started=true
button1.title=String(hitCount)
hitCount+=1
}
}
You can't initialise one variable with another at the top level in your class. Looking at your code I don't think that originalCount needs to be a property, move it inside startGame() instead and make it a local variable and also use let since it isn't changing
var countdown=10
func startGame(){
let originalCount = countDown
if(countDown>0 || started==true){
...
}
So I just started programming and I am now getting this error.
It occurs every time I press the button more times than there are Pizzas in the list.
Full error code: Thread 1: EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP, subcode=0x0):
Here`s my code so far:
import UIKit
var pizzaNumber = 0
var pizzaNames = ["Skinke Pizza", "Salat Pizza", "Pepperoni Pizza"]
let priser = [65,70,65]
var totalProdukt = pizzaNames.count
class ViewController: UIViewController {
#IBOutlet weak var produktNavn: UILabel!
#IBAction func rightButton(_ sender: UIButton) {
pizzaNumber+=1
showPizza()
}
#IBAction func leftButton(_ sender: UIButton) {
pizzaNumber-=1
if pizzaNumber < 0 {
pizzaNumber = 0
}
showPizza()
}
func showPizza() {
if pizzaNumber > totalProdukt {
pizzaNumber = pizzaNames.count
} else {
self.produktNavn.text = pizzaNames[pizzaNumber]
}
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
You should make sure that pizzaNumber-1 can never be bigger than the number of elements in your array to ensure that you are never trying to access an index that doesn't exist. This can be easily done by changing totalProdukt to be a computed variable. This way, the value of the variable will always be updated when you are trying to access it.
var totalProdukt: Int {
return pizzaNames.count
}
Also bear in mind that array indexing starts at 0, so you need
if pizzaNumber >= totalProdukt {
pizzaNumber = pizzaNames.count-1
} else {
self.produktNavn.text = pizzaNames[pizzaNumber]
}
Bear in mind that with your current code, there's no need for storing the count of the array in a separate variable, since you are only using it at one place in code.
Moreover, the cleanest solution is to check the value before actually increasing it rather than when using it, this way in showPizzas you don't need to do any checks, just update the label:
class ViewController: UIViewController {
#IBOutlet weak var produktNavn: UILabel!
#IBAction func rightButton(_ sender: UIButton) {
if pizzaNumber < pizzas.count-1 {
pizzaNumber+=1
}
showPizza()
}
#IBAction func leftButton(_ sender: UIButton) {
if pizzaNumber > 0 {
pizzaNumber-=1
}
showPizza()
}
func showPizza() {
self.produktNavn.text = pizzaNames[pizzaNumber]
}
}
Here's how to fix your error
func showPizza() {
if pizzaNumber >= totalProdukt { // << Added '=' since pizzaNames[pizzaNames.count] is out of bounds
pizzaNumber = pizzaNames.count - 1
} else {
self.produktNavn.text = pizzaNames[pizzaNumber]
}
}
Im developing a quiz app and there is a second view controller that appears after the initial view controller where you are asked to answer a question. On the second view controller you the user must press a button to return to the initial view controller to be asked another question. However when I segue back from the second view controller I believe a new instance of the initial view controller is being created and the user is asked questions they have already answered. The code in the swift file for my initial view controller is constructed that when once a user is asked a question once that question is removed from an array by it's index. How could I make it to where a new instance of the initial view controller isn't created from segueing from the second view controller? Or is there a way the second view controller can access the same methods as the initial view controller?
Here is my code for the initial view controller:
import UIKit
class ViewController: UIViewController {
var questionList = [String]()
func updateCounter() {
counter -= 1
questionTimer.text = String(counter)
if counter == 0 {
timer.invalidate()
wrongSeg()
counter = 15
}
}
func randomQuestion() {
//random question
if questionList.isEmpty {
questionList = Array(QADictionary.keys)
questionTimer.text = String(counter)
}
let rand = Int(arc4random_uniform(UInt32(questionList.count)))
questionLabel.text = questionList[rand]
//matching answer values to go with question keys
var choices = QADictionary[questionList[rand]]!
questionList.remove(at: rand)
//create button
var button:UIButton = UIButton()
//variables
var x = 1
rightAnswerBox = arc4random_uniform(4)+1
for index in 1...4
{
button = view.viewWithTag(index) as! UIButton
if (index == Int(rightAnswerBox))
{
button.setTitle(choices[0], for: .normal)
}
else {
button.setTitle(choices[x], for: .normal)
x += 1
}
randomImage()
}
}
let QADictionary = ["Who is Thor's brother?" : ["Atum", "Loki", "Red Norvell", "Kevin Masterson"], "What is the name of Thor's hammer?" : ["Mjolinr", "Uru", "Stormbreaker", "Thundara"], "Who is the father of Thor?" : ["Odin", "Sif", "Heimdall", "Balder"]]
//wrong view segue
func wrongSeg() {
performSegue(withIdentifier: "incorrectSeg", sender: self)
}
//proceed screen
func rightSeg() {
performSegue(withIdentifier: "correctSeg", sender: self)
}
//variables
var rightAnswerBox:UInt32 = 0
var index = 0
//Question Label
#IBOutlet weak var questionLabel: UILabel!
//Answer Button
#IBAction func buttonAction(_ sender: AnyObject) {
if (sender.tag == Int(rightAnswerBox))
{
rightSeg()
print ("Correct!")
}
if counter != 0 {
counter = 15
questionTimer.text = String(counter)
}
else if (sender.tag != Int(rightAnswerBox)) {
wrongSeg()
print ("Wrong!")
timer.invalidate()
questionList = []
}
randomQuestion()
}
override func viewDidAppear(_ animated: Bool)
{
randomQuestion()
}
//variables
var counter = 15
var timer = Timer()
#IBOutlet weak var questionTimer: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
timer = Timer.scheduledTimer(timeInterval: 1, target:self, selector: #selector(ViewController.updateCounter), userInfo: nil, repeats: true)
}
Here's the code to the second view controller:
import UIKit
class ContinueScreen: UIViewController {
//correct answer label
#IBOutlet weak var correctLbl: UILabel!
//background photo
#IBOutlet weak var backgroundImage: UIImageView!
func backToQuiz() {
if let nav = self.navigationController {
nav.popViewController(animated: true)
}
else {
self.dismiss(animated: true, completion: nil)
}
}
#IBAction func `continue`(_ sender: Any) {
backToQuiz()
}
What you need, sir is a delegate or an unwind segue. I far prefer delegates because they're easier to understand and I think a bit more powerful.
In your ContinueScreen view controller define a protocol similar to this:
protocol QuizCompletedDelegate {
func completedQuiz()
func canceledQuiz()
}
Also in your ContinueScreen view controller you need to declare an optional delegate of type QuizCompletedDelegate
var delegate: QuizCompletedDelegate?
... and use that delegate to call the functions when appropriate:
#IBAction func didPressContinue(_ sender: Any) {
if allQuestionsAnswered == true {
delegate.completedQuiz()
} else {
delegate.cancelledQuiz()
}
}
In your initial view controller is where you implement the functions for the protocol:
extension ViewController: QuizCompletedDelegate {
func completedQuiz() {
//Handle quiz complete
}
func cancelledQuiz() {
//Handle quiz cancelled
}
}
Then the last thing you need to do is set the delegate of your ContinueScreen view controller in the prepareForSegue function of your initial view controller.
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if segue.identifier == "showContinueScreen" {
let continueVC = segue.destination as! ContinueScreen
continueVC.delegate = self
}
}
Remove the call to randomQuestion() on your initial view controller's ViewDidAppear, and you're in business!
It shouldn't create a new View Controller when you go back. If it does - it's very bad - and you should re-architect the flow of your app... To pass data forward, we should use Dependency Injection. To pass data to the previous view controller - use the iOS Delegation Pattern. I recommend to spend 30-40 mins to read (and understand this article), and it will make things more clear for you in the future: http://matteomanferdini.com/how-ios-view-controllers-communicate-with-each-other/.
I am developing a quiz app where the user is asked a question at random and must answer it on the initial view controller. If the user picks correctly, a second view controller appears which contains a button that pops the view controller off the navigation stack and goes back to the initial view controller to finish the other questions. However, I have a timer that I want to reset (start at 15s) every time that second view controller is popped and the initial view controller appears with the next question. How would I accomplish this task? I already have the countdown timer code in my swift file. I just need to know how to get it to start from scratch every time the second view controller is popped/removed.
Here's my code for the initial view controller:
import UIKit
extension ViewController: QuizCompletedDelegate {
func continueQuiz() {
randomQuestion()
}
}
class ViewController: UIViewController {
var questionList = [String]()
func updateCounter() {
counter -= 1
questionTimer.text = String(counter)
if counter == 0 {
timer.invalidate()
wrongSeg()
counter = 15
}
}
func randomQuestion() {
//random question
if questionList.isEmpty {
questionList = Array(QADictionary.keys)
}
let rand = Int(arc4random_uniform(UInt32(questionList.count)))
questionLabel.text = questionList[rand]
//matching answer values to go with question keys
var choices = QADictionary[questionList[rand]]!
questionList.remove(at: rand)
//create button
var button:UIButton = UIButton()
//variables
var x = 1
rightAnswerBox = arc4random_uniform(4)+1
for index in 1...4 {
button = view.viewWithTag(index) as! UIButton
if (index == Int(rightAnswerBox)) {
button.setTitle(choices[0], for: .normal)
} else {
button.setTitle(choices[x], for: .normal)
x += 1
}
randomImage()
}
}
let QADictionary = ["Who is Thor's brother?" : ["Atum", "Loki", "Red Norvell", "Kevin Masterson"], "What is the name of Thor's hammer?" : ["Mjolinr", "Uru", "Stormbreaker", "Thundara"], "Who is the father of Thor?" : ["Odin", "Sif", "Heimdall", "Balder"]]
//wrong view segue
func wrongSeg() {
performSegue(withIdentifier: "incorrectSeg", sender: self)
}
//proceed screen
func rightSeg() {
performSegue(withIdentifier: "correctSeg", sender: self)
}
//variables
var rightAnswerBox:UInt32 = 0
var index = 0
//Question Label
#IBOutlet weak var questionLabel: UILabel!
//Answer Button
#IBAction func buttonAction(_ sender: AnyObject) {
if (sender.tag == Int(rightAnswerBox)) {
rightSeg()
print ("Correct!")
}
if counter != 0 {
counter = 15
questionTimer.text = String(counter)
} else if (sender.tag != Int(rightAnswerBox)) {
wrongSeg()
print ("Wrong!")
timer.invalidate()
questionList = []
}
}
override func viewDidAppear(_ animated: Bool) {
randomQuestion()
}
//variables
var counter = 15
var timer = Timer()
#IBOutlet weak var questionTimer: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
timer = Timer.scheduledTimer(timeInterval: 1, target:self, selector: #selector(ViewController.updateCounter), userInfo: nil, repeats: true)
}
}
Here's the code to the second view controller:
class ContinueScreen: UIViewController {
var delegate: QuizCompletedDelegate?
//correct answer label
#IBOutlet weak var correctLbl: UILabel!
//background photo
#IBOutlet weak var backgroundImage: UIImageView!
func backToQuiz() {
delegate?.continueQuiz()
if let nav = self.navigationController {
nav.popViewController(animated: true)
} else {
self.dismiss(animated: true, completion: nil)
}
}
#IBAction func `continue`(_ sender: Any) {
backToQuiz()
}
override func viewDidLoad() {
super.viewDidLoad()
}
}
How to make countdown timer reset after button push on different view
controller?
So if you can get the reference of yourView controller where you have
setup the timer then you can access counter variable from previous
view controller inside your second viewController and when pushed the
button just reset to 0.
If above approach is not possible for you then another way is create
the static variable and access it anywhere and reset like this:-
static var counter = 0
if you are popping/removing the 2nd view controller and thus returning to the first, you could reset the timer in your viewDidAppearfunc in your 1st view controller. this way the timer restarts every time the view appears - the first time, and whenever the 2nd pops.
like it says in the title, i am trying to change label text upon click of a button. Error appears at line self.playerChoice.text = "You: Rock"
import UIKit
class ViewController: UIViewController {
var player : Int = Int()
#IBOutlet weak var readyLabel: UILabel!
#IBAction func noButton(sender: AnyObject) {
exit(0)
}
// ---------------------------------------------------------
#IBOutlet var computerChoice: UILabel!
#IBOutlet var playerChoice: UILabel!
#IBOutlet var score: UILabel!
// Variables -------------------------------------------------
let Rock : String = "Rock"
let Paper : String = "Paper"
let Scissors : String = "Scissors"
//------------------------------------------------------------
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
// ----------------------------------------------------------------
#IBAction func rockButton(rockbut: UIButton) {
player = 0
var ai = arc4random_uniform(3)
self.playerChoice.text = "You: Rock"
}
#IBAction func paperButton(paperbut: UIButton) {
player = 1
var ai = arc4random_uniform(3)
self.playerChoice.text = "You: Paper"
}
#IBAction func scissorsButton(scissorsbut: UIButton) {
player = 2
var ai = arc4random_uniform(3)
self.playerChoice.text = "You: Scissors"
}
}
I ran into this problem and it turned out that the labels that I was trying to edit didn't exist at the time the code ran.
Turns out I was referencing the same view controller from a parent view and a child container view. The labels I was trying to change were only in the container view but as both views loaded it ran the view controller for both so it tried to find the labels that didn't exist in the parent view and threw the above error.
So the lesson I learned... If a reference to a view object is throwing a NIL..
The View isn't properly mapped to the View Controller.
The object within the view isn't mapped to the referencing IBOutlet.
Or as in my case, there are multiple views connected to the same View Controller and references to view objects in one view are not being found in the other.
Looks like player choice is not initialized.
#IBOutlet var playerChoice: UILabel!
Maybe the connection between the outlet and InterfaceBuilder/Storyboard is lost. Try to connect it again.
I've created a small demo and everything works fine:
Check if the circles at the left side of your IBOutlet are filled. Otherwise the connection is lost.
What fixed this for me (and it gets me everytime, especially when you are new to using storyboards) is to make sure that you are initializing your view controller like so :
slideShowVC = (UIStoryboard(name: "Main",bundle: nil).instantiateViewControllerWithIdentifier("WWPhotoSlideShowVC") as! WWPhotoSlideShowVC)
instead of the stand alone xib way :
slideShowVC = WWSlideShowVC()
Or else all your outlets will be nil na many headaches will soon follow.
I ran into the same issue in Xcode 6.2.
I use individual XIBs instead of storyboards. The problem for me was that with Swift, Xcode does not automatically associate the XIB with the view controller if the names are the same. Hence the IBOutlets for the labels are pointing to nil giving the fatal.
You can change the viewcontroller.xib to be called modulename.viewcontroller.xib so that xcode can associate it with the view controller and the issue goes away.
More options are mentioned on this thread:
Can't Load UIViewController XIB file in Storyboard in Swift
I have tried this code and it working fine for me:
class ViewController: UIViewController {
var player : Int = Int() //Declare this globally
#IBOutlet weak var readyLabel: UILabel!
#IBAction func noButton(sender: AnyObject) {
exit(0)
}
// ---------------------------------------------------------
#IBOutlet var computerChoice: UILabel!
#IBOutlet var playerChoice: UILabel!
#IBOutlet var score: UILabel!
// Variables -------------------------------------------------
let Rock : String = "Rock"
let Paper : String = "Paper"
let Scissors : String = "Scissors"
//------------------------------------------------------------
#IBAction func rockButton(rockbut: UIButton) {
player = 0
var ai = arc4random_uniform(3)
self.playerChoice.text = "You: Rock"
}
#IBAction func paperButton(sender: UIButton) {
player = 1
var ai = arc4random_uniform(3)
self.playerChoice.text = "You: Paper"
}
#IBAction func scissorsButton(sender: UIButton) {
player = 2
var ai = arc4random_uniform(3)
self.playerChoice.text = "You: Scissors"
}
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
var p : String = "Undecided"
if (player == 0) {
var p: String = "Rock"
} else if (player == 1) {
var p: String = "Paper"
} else if (player == 2) {
var p: String = "Scissors"
}
}
}