CODEWITHSUNDEEP
iosobjective-ciphonecocoa-touchuikit
Thanks
Thanks

Reputation: 40329

How can I delay a method call for 1 second?

Is there an easy way delay a method call for 1 second?

I have a UIImageView that reacts on a touch event. When the touch is detected, some animations happen in the app. After one second, I want to call another method. In this case, I can't use the animationDidStop selector.

Upvotes: 171

Views: 182132

Answers (11)

Salman Ghumsani
Salman Ghumsani

Reputation: 3657

Swift 2.x

let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
 dispatch_after(delayTime, dispatch_get_main_queue()) {
 print("do some work")
}

Swift 3.x --&-- Swift 4

DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
    print("do some work")
}

or pass a escaping closure 

func delay(seconds: Double, completion: @escaping()-> Void) {
    DispatchQueue.main.asyncAfter(deadline: .now() + seconds, execute: completion)
}

Upvotes: 6

Sujeet Shrivastav
Sujeet Shrivastav

Reputation: 56

Use in Swift 3

perform(<Selector>, with: <object>, afterDelay: <Time in Seconds>)

Upvotes: 0

mcfedr
mcfedr

Reputation: 7975

You could also use a block

dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
    [object method]; 
});

Most of time you will want to use dispatch_get_main_queue, although if there is no UI in the method you could use a global queue.

Edit:

Swift 3 version:

DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
    object.method()
}

Equally, DispatchQueue.global().asyncAfter(... might also be a good option.

Upvotes: 202

Kevin ABRIOUX
Kevin ABRIOUX

Reputation: 17685

There is a Swift 3 solution from the checked solution :

self.perform(#selector(self.targetMethod), with: self, afterDelay: 1.0)

And there is the method

@objc fileprivate func targetMethod(){

}

Upvotes: 1

Tom Arleth
Tom Arleth

Reputation: 163

NOTE: this will pause your whole thread, not just the one method.
Make a call to sleep/wait/halt for 1000 ms just before calling your method?

Sleep(1000); // does nothing the next 1000 mSek

Methodcall(params); // now do the real thing

Edit: The above answer applies to the general question "How can I delay a method call for 1 second?", which was the question asked at the time of the answer (infact the answer was given within 7 minutes of the original question :-)). No Info was given about the language at that time, so kindly stop bitching about the proper way of using sleep i XCode og the lack of classes...

Upvotes: -35

Milianoo
Milianoo

Reputation: 1476

Best way to do is : 

[self performSelector:@selector(YourFunctionName) 
           withObject:(can be Self or Object from other Classes) 
           afterDelay:(Time Of Delay)];

you can also pass nil as withObject parameter.

example : 

[self performSelector:@selector(subscribe) withObject:self afterDelay:3.0 ];

Upvotes: 132

Alex Cio
Alex Cio

Reputation: 6052

There are already a lot of answers and they are all correct. In case you want to use the dispatch_after you should be looking for the snippet which is included inside the Code Snippet Library at the right bottom (where you can select the UI elements).

enter image description here

So you just need to call this snippet by writing dispatch in code:

enter image description here

Upvotes: 23

Nitesh
Nitesh

Reputation: 1389

You can do this

[self performSelector:@selector(MethodToExecute) withObject:nil afterDelay:1.0 ];

Upvotes: 8

Jim
Jim

Reputation: 4711

performSelector:withObject:afterDelay:

Document Reference

Upvotes: 258

Geri Borb&#225;s
Geri Borb&#225;s

Reputation: 16588

You can also:

[UIView animateWithDuration:1.0
                 animations:^{ self.view.alpha = 1.1; /* Some fake chages */ }
                 completion:^(BOOL finished)
{
    NSLog(@"A second lapsed.");
}];

This case you have to fake some changes to some view to get the animation work. It is hacky indeed, but I love the block based stuff. Or wrap up @mcfedr answer below.

waitFor(1.0, ^
{
    NSLog(@"A second lapsed");
});

typedef void (^WaitCompletionBlock)();
void waitFor(NSTimeInterval duration, WaitCompletionBlock completion)
{
    dispatch_after(dispatch_time(DISPATCH_TIME_NOW, duration * NSEC_PER_SEC),
                   dispatch_get_main_queue(), ^
    { completion(); });
}

Upvotes: 9

Nimit Parekh
Nimit Parekh

Reputation: 16864

You can use the perform selector for after the 0.1 sec delay method is call for that following code to do this.

[self performSelector:@selector(InsertView)  withObject:nil afterDelay:0.1];

Upvotes: 16

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