Manage Multiple Timer in Swift using UIView

kunal prasad

17 November 2023

Timer

Sometimes we need to manage multiple timers in UIView so if we recreate multiple timers then it will show wrong value so for this we need to create a single Timer class for every single UIView, for doing this we need to follow some steps:

1: Create an array of timers:

var timer = [Timer]()

2: Now in for loop where you creating multiple views here you have to append the timer and also the UILabel on which the value will show :

if ((data.object(forKey: "mainDeal") as? NSArray)?.count)! > 0{

let dealofDayTime = UILabel(frame: CGRect(x: 10, y: Y, width: categoryBlock.frame.size.width - 20, height: 30))
                    dealofDayTime.textColor = UIColor.white
                    dealofDayTime.tag = i
                    dealofDayTime.textAlignment = .left
                    dealofDayTime.font = UIFont(name: BOLDFONT, size: 14)
                    dealofDayTime.text = formattedString
                    categoryBlock.addSubview(dealofDayTime);



var details = [String:AnyObject]();
                    details = ["label":dealofDayTime];
                    
                    self.timer.append(Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.runScheduledTask), userInfo: details, repeats: true))

}

if ((data.object(forKey: "mainDeal") as? NSArray)?.count)! > 0{

let dealofDayTime = UILabel(frame: CGRect(x: 10, y: Y, width: categoryBlock.frame.size.width - 20, height: 30))

dealofDayTime.textColor = UIColor.white

dealofDayTime.tag = i

dealofDayTime.textAlignment = .left

dealofDayTime.font = UIFont(name: BOLDFONT, size: 14)

dealofDayTime.text = formattedString

categoryBlock.addSubview(dealofDayTime);

var details = [String:AnyObject]();

details = ["label":dealofDayTime];

self.timer.append(Timer.scheduledTimer(timeInterval: 1.0, target: self, selector: #selector(self.runScheduledTask), userInfo: details, repeats: true))

}

3: Now define the function:

func runScheduledTask(_ runningTimer: Timer) {
        
        var dict = runningTimer.userInfo as! [String:AnyObject];
        let label:UILabel = dict["label"] as! UILabel
    
        var remainingSeconds = dealOfTheDay.object(at: label.tag) as! Double;
        remainingSeconds -= 1
       
        
        if remainingSeconds == 0  || remainingSeconds < 0{
            runningTimer.invalidate()
            label.text = ""
        }
        else{
            let formatter = DateComponentsFormatter()
            formatter.allowedUnits = [.day,.hour, .minute, .second]
            formatter.unitsStyle = .positional
            let formattedString = formatter.string(from: TimeInterval(remainingSeconds))!
            label.text = formattedString.uppercased()
            dealOfTheDay.replaceObject(at: label.tag, with: remainingSeconds)
            
        }
   
    }

func runScheduledTask(_ runningTimer: Timer) {

var dict = runningTimer.userInfo as! [String:AnyObject];

let label:UILabel = dict["label"] as! UILabel

var remainingSeconds = dealOfTheDay.object(at: label.tag) as! Double;

remainingSeconds -= 1

if remainingSeconds == 0 || remainingSeconds < 0{

runningTimer.invalidate()

label.text = ""

}

else{

let formatter = DateComponentsFormatter()

formatter.allowedUnits = [.day,.hour, .minute, .second]

formatter.unitsStyle = .positional

let formattedString = formatter.string(from: TimeInterval(remainingSeconds))!

label.text = formattedString.uppercased()

dealOfTheDay.replaceObject(at: label.tag, with: remainingSeconds)

}

Note:

here “dealOfTheDay” is an array of interval time:

“dealOfTheDay” = [100,200,145….] so on

4: for reinitializing you need to do like that

for i in 0..<self.timer.count{
            let t:Timer = timer[i];
            t.invalidate()
        }
        self.timer = [Timer]()

for i in 0..<self.timer.count{

let t:Timer = timer[i];

t.invalidate()

}

self.timer = [Timer]()

That’s All
For any queries, feel free to ask.