dispatch_async in Swift

Question

I am really new to this programming language called swift.

I use

dispatch_async(dispatch_get_main_queue(), ^{
});

this method for async-dispatch-queue in xcode 5.

I want implement it in swift language.

how do i implement dispatch queue in or swift?

http://stackoverflow.com/q/24034544/1402846 – Pang Dec 27 '14 at 06:46 — Pang, Dec 27 '14 at 06:46

score 3 · Answer 1 · answered Sep 21 '17 at 22:59

3

For those of you viewing this post three years later as I did, the Swift functions have been improved. Now you can write:

DispatchQueue.main.async(execute: { () -> Void in
    // Your code here
})

answered Sep 21 '17 at 22:59

Mark Radbourne

477
2
7

score 2 · Accepted Answer · answered Dec 27 '14 at 06:55

You can use this syntax:

dispatch_async(dispatch_get_main_queue(), {
    println("hello")
})

However, when the last argument is a block, Swift lets you put it outside the parentheses. This makes the function seem more like a control structure (like a for or if statement). Thus you can do this:

dispatch_async(dispatch_get_main_queue()) {
    println("hello")
}

score 1 · Answer 3 · answered Dec 27 '14 at 06:51

Xcode gives you an easy help with that....

Just type in

dispatch_async and hit enter... Than XCode gives you something like this...

dispatch_async(queue: dispatch_queue_t!, block: dispatch_block_t! () -> Void)

now take your mouse and double-click on block: dispatch_block_t! () -> Void and XCode will automatically change this to a working closure expression :-)

dispatch_async(dispatch_get_main_queue(), { () -> Void in
     //Your Code here       
})

dispatch_async in Swift

3 Answers3