MarkoFrontDev MarkoFrontDev - 5 months ago 31
iOS Question

iOS Swift countdown - need to show text after 2 seconds and hide it after 6 seconds

I need to build an iOS Swift single-page app which has a countdown timer for 60:00 minutes. After 2 seconds I need to show a

UILabel
, hide it after 6 seconds and then show another text after that. This is my code so far for the timer:

var startTime = NSTimeInterval()
var timer = NSTimer()

func startCountdownTimer() {

var currentTime = NSDate.timeIntervalSinceReferenceDate()

//Find the difference between current time and start time.
var elapsedTime: NSTimeInterval = 3600-(currentTime-startTime)

//Calculate the minutes in elapsed time.
let minutes = UInt8(elapsedTime / 60.0)
elapsedTime -= (NSTimeInterval(minutes) * 60)

//Calculate the seconds in elapsed time.
var seconds = UInt8(elapsedTime)
elapsedTime -= NSTimeInterval(seconds)

//Add the leading zero for minutes and seconds and store them as string constants
let strMinutes = minutes > 9 ? String(minutes):"0" + String(minutes)
let strSeconds = seconds > 9 ? String(seconds):"0" + String(seconds)

//Concatenate minutes and seconds and assign it to the UILabel
timerLabel.text = "\(strMinutes):\(strSeconds)"

}


I've tried doing something like this:

if elapsedTime == 2 {
introTextLabel.hidden = false
}


or this:

if (elapsedTime: NSTimeInterval(seconds)) == 2 {
introTextLabel.hidden = false
}


But it doesn't work.
Can anyone help?

introTextLabel
- Label to show text in

timerLabel
- Label for timer

Answer

You can use the handy delay() function written by matt.

func delay(delay:Double, closure:()->()) {
    dispatch_after(
        dispatch_time(
            DISPATCH_TIME_NOW,
            Int64(delay * Double(NSEC_PER_SEC))
        ),
    dispatch_get_main_queue(), closure)
}

Use it like this:

// Wait two seconds:
delay(2.0) {
    print("Hello!")
}