Pass DispatchTime as an argument in DispatchAfter

Question

There is some old code I am processing. Following are two lines (old code) which I am not able to convert or rather understand :

let dispatchTime = dispatch_time(dispatch_time_t(DispatchTime.now()), Int64(seconds * Double(NSEC_PER_SEC)))  
dispatch_after(dispatchTime, dispatch_get_main_queue(), block)

Now, to make it work in Swift 4.x, this is what I did for line 1 :

let dispatchTime =  DispatchTime(uptimeNanoseconds: UInt64(Int64(seconds * Double(NSEC_PER_SEC))))

I made this conversion on the basis of initialiser description as mentioned here :

Creates a time relative to the system clock that ticks since boot.

Since they say that it creates a relative time, DispatchTime.now() is already considered. Not to mention, I might be wrong. Please do correct me.

For the second line, I am unaware as to how to pass DispatchTime as an argument in DispatchAfter.

This didnt help you ??https://stackoverflow.com/questions/37801436/how-do-i-write-dispatch-after-gcd-in-swift-3-and-4 — Vinaykrishnan, Apr 16 '18 at 07:44

Milan Nosáľ · Accepted Answer · 2018-04-16T08:08:12.017

8

This is what you want in Swift 3+:

let seconds = 2.0
// dispatchTime 2 seconds from now:
let dispatchTime: DispatchTime = DispatchTime.now() + seconds
DispatchQueue.main.asyncAfter(deadline: dispatchTime) {
    // code to be executed
}

edited Apr 16 '18 at 08:08

answered Apr 16 '18 at 07:39

Milan Nosáľ

19,169
4
55
90

So where does DispatchTime comes into picture - in the new syntax ? – Nitish Apr 16 '18 at 07:41
Makes much sense now. – Nitish Apr 16 '18 at 08:06

Pass DispatchTime as an argument in DispatchAfter

1 Answers1