Xcode Swift Stopwatch App

Question

I have a stopwatch app I'm making that currently shows the minutes, seconds and milliseconds on a UILabel. It has a 'Start' button and a 'Stop' button. The code is below. How do I add hours to it? Also how do I make it continue where it was, when I stopped it? Currently if I press start again, it resets and starts over. I'll add a reset button later.

//Variables
var startTime = NSTimeInterval()

//Start Button
@IBAction func start(sender: AnyObject) {
   let aSelector : Selector = “updateTime”
   timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: aSelector, userInfo: nil, repeats: true)
   startTime = NSDate.timeIntervalSinceReferenceDate()
}

//Stop Button
@IBAction func stop(sender: AnyObject) {
   timer.invalidate()
}

//Update Time Function
func updateTime() {

   var currentTime = NSDate.timeIntervalSinceReferenceDate()

   //Find the difference between current time and start time.

   var elapsedTime: NSTimeInterval = currentTime - startTime

   //calculate the minutes in elapsed time.

   let minutes = UInt8(elapsedTime / 60.0)

   elapsedTime -= (NSTimeInterval(minutes) * 60)

   //calculate the seconds in elapsed time.

   let seconds = UInt8(elapsedTime)

   elapsedTime -= NSTimeInterval(seconds)

   //find out the fraction of milliseconds to be displayed.

   let fraction = UInt8(elapsedTime * 100)

   //add the leading zero for minutes, seconds and millseconds and store them as string constants

   let strMinutes = String(format: "%02d", minutes)
   let strSeconds = String(format: "%02d", seconds)
   let strFraction = String(format: "%02d", fraction)

   //concatenate minuets, seconds and milliseconds as assign it to the UILabel

   displayTimeLabel.text = “\(strMinutes):\(strSeconds):\(strFraction)”

}

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score 3 · Accepted Answer · edited May 23 '17 at 10:31

3

You can calculate hours so

elapsedtime / 3600

Read there more NSTimeInterval to HH:mm:ss?

edited May 23 '17 at 10:31

Community

1
1

answered Apr 23 '15 at 19:39

cmashinho

605
5
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Great thank you. Do you know how to make it so it continues to count on the stopwatch and not reset when I click start again? – ChallengerGuy Apr 23 '15 at 22:42
@ChallengerGuy please write me to email – cmashinho Apr 24 '15 at 19:53
How do I do that? I"m new to this whole stack overflow thing. – ChallengerGuy Apr 25 '15 at 21:45

score 0 · Answer 2 · answered Jan 15 '16 at 15:45

To make continues to count on the stopwatch:

Create var stopTime : NSTimeInterval = 0

When stop() function is called, insert this code:

 stopTime = elapsedTime

In start() function, replace to:

elapsedTime = (currentTime - startTime) + stopTime

Or You can use NSDate(), NSDateFormatter() to solve this problem. Reference here enter link description here

Xcode Swift Stopwatch App

2 Answers2