How to run code on the main thread using GCD async()
Swift offers you two ways to run code on the main thread: GCD and performSelector(onMainThread:). The first option looks like this:
DispatchQueue.main.async { [unowned self] in
self.yourCodeHere()
}The second option looks like this:
performSelector(onMainThread: #selector(yourCodeHere), with: nil, waitUntilDone: false)The GCD option (the first one) has the advantage that you can write your code inline, whereas the second one requires a dedicated method you can call.
Sponsored You’re already busy updating your app for Swift 4.2 and iOS 12, so why not let Instabug help you find and fix bugs? Add just two lines of code to your project and receive comprehensive reports with all the feedback you need to ship a world-class app – click here to learn more!
Available from iOS 4.0 – see Hacking with Swift tutorial 9
Did this solution work for you? Please pass it on!
Other people are reading…
- How to copy objects in Swift using copy()
- How to parse JSON using JSONSerialization
- How to detect which country a user is in
- How to generate a random identifier using UUID
- How to make your app open with a custom URL scheme
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
Want to build macOS apps?
Hacking with macOS delivers 18 awesome projects that teach you macOS development in no time – take control of your desktop today!
