How to loop NSTimer in SWIFT with a specific number of counting

问题

I am trying to loop a timer with a specific number of counting... eg... 1, 2, 3, 4, 5

then loop again, the same counting, 10 times, then stop.

I was able to do the counting, but I can't do the looping of the counting.

What am I doing wrong?

var times = 0
var stopCounting = 10

@IBAction func buttonPressed(sender: UIButton) {
   self.startTimer()
}

func startTimer(){
        self.timer = NSTimer.scheduledTimerWithTimeInterval(1.0, target: self, selector: Selector("startCounting"), userInfo: nil, repeats: true)
    }

func startCounting (){

times += 1
if times < stopCounting + 1{

        if counter > -1 && counter < 6 {
            counting.text = String(counter++)
        } else if counter == Int(counting.text) {
            counting.text = "0"
        }

    }

回答1:

import UIKit

class ViewController: UIViewController {

    @IBOutlet weak var strTime: UILabel!

    var timer = NSTimer()
    var endTime: NSTimeInterval = 0
    var now: NSTimeInterval { return NSDate().timeIntervalSinceReferenceDate }
    var times = 0

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }

    func updateText(){
        let time = Int(ceil(endTime - now))

        if time == 0 {
            times++
            if times == 10 {
                strTime.text = "end"
                timer.invalidate()
            }
            endTime = NSDate().timeIntervalSinceReferenceDate + 5
        } else {
            strTime.text = time.description
        }
    }

    @IBAction func buttonPressed(sender: UIButton) {
        timer = NSTimer.scheduledTimerWithTimeInterval(0.1, target: self, selector: "updateText", userInfo: nil, repeats: true)
        endTime = NSDate().timeIntervalSinceReferenceDate + 5
        sender.hidden = true
    }
}

to make it count from 1 to 5 you need to change from ceil to floor, abs() and add +1

func updateText(){
    let time = Int(floor(abs(endTime - now - 5)))
    if time == 5 {
        times++
        if times == 10 {
            strTime.text = "10" + "     " + "0"
            timer.invalidate()
        }
        endTime = NSDate().timeIntervalSinceReferenceDate + 5
    } else {
        strTime.text = times.description + "     " + (time+1).description
    }
}

回答2:

Never done swift, but took a stab in the dark, why not.

var loops = 5        // Number of times to loop the counting
var countTo = 10     // Number to count to
var loopCount = 0    // Number of loops

@IBAction func buttonPressed(sender: UIButton) {
    self.timer = NSTimer.scheduledTimerWithTimeInterval(1.0, 
                                    target: self, 
                                    selector: Selector("startCounting"),
                                    userInfo: nil, 
                                    repeats: true)
}

func startCounting (){
    // Loop from 1 to countTo, setting the text for each number
    for i in 1..countTo {
        counting.text = String(i)
    }

    // Done counting, reset to zero
    counting.text = "0"

    // Update the number of times the counting has run
    loopCount++

     // If have completed all the loops, invalidate the timer
    if (loopCounter >= loops) {
        self.timer.invalidate()
    }
}

来源：https://stackoverflow.com/questions/29873055/how-to-loop-nstimer-in-swift-with-a-specific-number-of-counting

标签

swift

nstimer