Creating multiple Countdown Timers in Swift - ios

Question

Okay so I'm trying to add a 2 seconds countdown timer in a label that activates whenever the user double taps the screen.
So upon doubletapping, the user would find a new label created with the number "2" then a second later "1" then "0".
I can do this perfectly for just 1 timer. When the user double taps to create a second timer, or more, the app crashes.
I found that this is due to the declaration of the variables being made in the class instead of in the function to allow the timer function to retrieve such declarations as the label.
If I found a way to make the timer function inside another function instead of under class it will work fine.
So here's the code that works only when 1 timer is being deployed.
Under Class:
var BTTimer = NSTimer ()
var BTCounter = 2
let BT = SKLabelNode
Under Function touchesBegan:
let B = SKSpriteNode(imageNamed: "B 110.png")
let Touch : UITouch! = touches.first
let TouchLocation = Touch.locationInNode(self)
let PreviousTouchLocation = Touch.previousLocationInNode(self)
let Player = childNodeWithName("Player") as! SKSpriteNode
let xPos = Player.position.x + (TouchLocation.x - PreviousTouchLocation.x)
let yPos = Player.position.y + (TouchLocation.y - PreviousTouchLocation.y)
B.position = CGPointMake(xPos, yPos)
B.zPosition = -2
self.addChild(B)
BT.fontSize = 27;
BT.fontColor = UIColor.redColor()
BT.position = CGPointMake(xPos - 9, yPos - 30)
BT.zPosition = -1
self.addChild(BT)
BT.text = String(BTCounter);
BTTimer = NSTimer.scheduledTimerWithTimeInterval(1, target:self, selector: #selector(GameScene.updateBCounter), userInfo: nil, repeats: true)
}
}
Now under another function of the same class:
func updateBCounter() {
if(BTCounter > 0) {
BTCounter-=1
BT.text = String(BTCounter)
}
else if(BTCounter == 0) {
//Remove B
//Place C
}
I wish to change this so that the user is capable of producing as many timers as he wishes to deploy.

Answer 1

You can update updateBCounter like this:
func updateBCounter(timer: NSTimer)
Your selector is changed to #selector(GameScene.updateBCounter(_:)
When you schedule the timer, you can set userInfo to any dictionary and the timer sent to updateBCounter will have it in its userInfo property.
I don't know exactly what you are trying to do, but those are the tools to do multiple timers at once calling the same selector, but knowing which one you are dealing with.
Get rid of the properties keeping track of things and make keys in the userInfo dictionary instead.
You could use any object as userInfo (not just a dictionary), so you could also do:
class TimerData {
var counter: Int
var l: SKLabelNode
}