swift: stop countdown timer at zero

Question

I'm new to Swift - trying to build an app for iPhone/iPad. Hope you can help me.

I want to include a timer that counts down from 04:00 minutes to 00:00. It should then stop at zero and trigger a sound effect (which I haven't tried to implement yet). The countdown starts when you push a start button (in my code startTimer and stopTimer refer to the same button; however, the button is only pushed once at the beginning).

The timer starts and counts down just fine. It converts seconds into minutes as planned. However, my main problem is that I cannot get the countdown to stop at zero. It continues beyond as 00:0-1 etc. How do I fix this?

import Foundation
import UIKit
import AVFoundation


class Finale : UIViewController {



    @IBOutlet weak var timerLabel: UILabel!


    var timer = NSTimer()
    var count = 240
    var timerRunning = false




    override func viewDidLoad() {
        super.viewDidLoad()

    }



    func updateTime() {
        count--


        let seconds = count % 60
        let minutes = (count / 60) % 60
        let hours = count / 3600
        let strHours = hours > 9 ? String(hours) : "0" + String(hours)
        let strMinutes = minutes > 9 ? String(minutes) : "0" + String(minutes)
        let strSeconds = seconds > 9 ? String(seconds) : "0" + String(seconds)
        if hours > 0 {
            timerLabel.text = "\(strHours):\(strMinutes):\(strSeconds)"
        }

        else {
            timerLabel.text = "\(strMinutes):\(strSeconds)"
        }

    }



    @IBAction func startTimer(sender: AnyObject) {

        var timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("updateTime"), userInfo: nil, repeats: true)

    }

 func stopTimer() {

    if count == 0 {
        timer.invalidate()
        timerRunning = false
           }
    }



    @IBAction func stopTimer(sender: AnyObject) {
        timerRunning = false
     if count == 0 {
    timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("stopTimer"), userInfo: nil, repeats: true)
        timerRunning = true
        }}

}

http://stackoverflow.com/a/29583418/2303865 – Leo Dabus Jan 12 '16 at 16:36 — Leo Dabus, Jan 12 '16 at 16:36

score 2 · Answer 1 · answered Jan 12 '16 at 14:21

func updateTime() {
        count--


        let seconds = count % 60
        let minutes = (count / 60) % 60
        let hours = count / 3600
        let strHours = hours > 9 ? String(hours) : "0" + String(hours)
        let strMinutes = minutes > 9 ? String(minutes) : "0" + String(minutes)
        let strSeconds = seconds > 9 ? String(seconds) : "0" + String(seconds)
        if hours > 0 {
            timerLabel.text = "\(strHours):\(strMinutes):\(strSeconds)"
        }

        else {
            timerLabel.text = "\(strMinutes):\(strSeconds)"
        }
    stopTimer()
}

score 1 · Accepted Answer · answered Jan 12 '16 at 14:22

1

Remember, your timer doesn't count down to zero - you implement that in your code. The timer just fires every second.

In your updateTime function, you need to invalidate the timer, and call your sound function, when the timer runs out

answered Jan 12 '16 at 14:22

Russell

5,436
2
19
27

Thanks, Russell. How do I invalidate it? I now tried adding if count == 0 { timer.invalidate() timerRunning = false } to the updateTime function, but it's not stopping. – mojomo Jan 12 '16 at 14:31
That should do it - but you have two versions of timer ! You have one variable defined with class-wide scope, but the one you are using is only defined in the start function. You need to remove the 'var' before you initialise the timer so that you're only using the one variable – Russell Jan 12 '16 at 14:35

score 0 · Answer 3 · answered Jan 12 '16 at 14:48

0

Yay! It's working!! I used a mix of the two answers. I added stopTimer() to my updateTimer function, I deleted the "var" from the timer, and I deleted the last paragraph/IBAction of my code. Thank you so much guys! Now I'll try adding sound. :)

answered Jan 12 '16 at 14:48

mojomo

109
11

Cool - remember to flag the answers that helped you :-) – Russell Jan 12 '16 at 15:16

swift: stop countdown timer at zero

3 Answers3