Delaying function in swift [duplicate]

Question

This question already has an answer here:

• dispatch_after - GCD in Swift? 23 answers

I don't have a code to sample or anything, because I have no idea how to do it, but can someone please tell me how to delay a function with swift for a set amount of time?

Answer 1

You can use GCD (in the example with a 10 second delay):

Swift 2

let triggerTime = (Int64(NSEC_PER_SEC) * 10)
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, triggerTime), dispatch_get_main_queue(), { () -> Void in
    self.functionToCall()
})

Swift 3 and Swift 4

DispatchQueue.main.asyncAfter(deadline: .now() + 10.0, execute: {
    self.functionToCall()
})

Answer 2

Swift 3 Version for a delay of 10 seconds

unowned let unownedSelf = self

let deadlineTime = DispatchTime.now() + .seconds(10)
DispatchQueue.main.asyncAfter(deadline: deadlineTime, execute: { 
     unownedSelf.functionToCall()
})

Answer 3

 NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(3), target: self, selector: "functionHere", userInfo: nil, repeats: false)

This would call the function functionHere() with a 3 seconds delay

Answer 4

For adding argument to delay function.

First setup a dictionary then add it as the userInfo. Unwrap the info with the timer as the argument.

let arg : Int = 42
let infoDict : [String : AnyObject] = ["argumentInt", arg]

NSTimer.scheduledTimerWithTimeInterval(NSTimeInterval(3), target: self, selector: "functionHereWithArgument:", userInfo: infoDict, repeats: false)

Then in the called function

func functionHereWithArgument (timer : NSTimer)
{
    if let userInfo = timer.userInfo as? Dictionary<String, AnyObject>
    {
         let argumentInt : Int = (userInfo[argumentInt] as! Int)
    }
}