CODEWITHSUNDEEP
swiftnstimerviewdidload
Elia Döhler
Elia Döhler

Reputation: 21

Start a NSTimer when view loads

I have want to make a simple clock app where the colon blinks to make it look better. My code so far is:

@IBOutlet weak var clockLabel: UILabel!
var timerRunning = true
var timer = NSTimer()
var OnOff = 0
var colon = ":"
var hour = 0
var minute = 0

override func viewDidLoad() {
    super.viewDidLoad()
    clockLabel.text = ("\(hour)\(colon)\(minute)")
    timer = NSTimer.scheduledTimerWithTimeInterval(1, target: self, selector: "Counting", userInfo: nil, repeats: true)
}
override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
}

func Counting(){ 
    if OnOff == 1 {
    OnOff = 0
    colon = ":"
    clockLabel.text = ("\(hour)\(colon)\(minute)")
    }
    if OnOff == 0 {
    OnOff = 1
    colon = ""
    clockLabel.text = ("\(hour)\(colon)\(minute)")
    }
}

The way I would like this to work is that the timer starts at exactly that moment when the view loads. I don't want to have to press a button to make the colon start blinking. Thanks in advance

Upvotes: 0

Views: 194

Answers (1)

the_critic
the_critic

Reputation: 12820

I don't see any issue with your timer (Your question title suggests otherwise), as far as I can tell it should fire every second after the view loads.

One thing I did notice is an issue in your code execution path: The two consequent if statements overlap if you change the variable (in the first one), so read on to see my solution.

A little improvement I would make -- as the OnOff variable seems to be binary in nature -- let's make that a boolean type: 

var colonShown : Bool = false // this is your "OnOff" variable (changed it to be more clear to the reader + made it boolean (you treat it as a boolean, so why not make it boolean?))

And then, in your timing function (I renamed it to tick()): 

// renamed your Counting() function, no particular reason for that (sorry if that causes confusion) -- you can replace your Counting() function with this one (also make sure to update your timer selector that references the "Counting()" function on each "tick")
func tick(){ 
    colonShown = !colonShown // toggle boolean value
    colon = colonShown ? ":" : "" // neat one-liner for your if statement

    clockLabel.text = ("\(hour)\(colon)\(minute)")

}

Upvotes: 1

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