How to trigger action after x seconds in swiftUI

.delay is built-in to Swift animations. I achieved my goal of launching an animation 0.5 seconds after a view appeared with the following code:

 .onAppear(perform: {
    withAnimation(Animation.spring().delay(0.5)) {
         self.scale = 1.0
    }
 })

Create a delay, which then sets the @State property hasTimeElapsed to true when the time has elapsed, updating the view body.

With Swift 5.5 and the new concurrency updates (async & await), you can now use task(_:) like the following:

struct ContentView: View {
    @State private var hasTimeElapsed = false

    var body: some View {
        Text(hasTimeElapsed ? "Sorry, too late." : "Please enter above.")
            .task(delayText)
    }

    private func delayText() async {
        // Delay of 7.5 seconds (1 second = 1_000_000_000 nanoseconds)
        try? await Task.sleep(nanoseconds: 7_500_000_000)
        hasTimeElapsed = true
    }
}

See more info about Task.sleep(nanoseconds:) in this answer.


Older versions

Xcode 13.0+ now supports concurrency, backwards compatible! However, here is still the 'old' way to do it:

You can use DispatchQueue to delay something. Trigger it with onAppear(perform:) (which happens when the view first appears). You could also hook the delay up to a Button instead if wanted.

Example:

struct ContentView: View {
    @State private var hasTimeElapsed = false

    var body: some View {
        Text(hasTimeElapsed ? "Sorry, too late." : "Please enter above.")
            .onAppear(perform: delayText)
    }

    private func delayText() {
        // Delay of 7.5 seconds
        DispatchQueue.main.asyncAfter(deadline: .now() + 7.5) {
            hasTimeElapsed = true
        }
    }
}