SwiftUI: How can I display an alert on the very first start - swift

Question

I'm new in SwiftUI and I would like to show an alert when the user start the app for the first time. If the user opens the app a second (or third...) time, the alert should not come anymore.
struct ContentView: View {
#State var alertShouldBeShown = true
var body: some View {
VStack {
Text("Hello World!")
.alert(isPresented: $alertShouldBeShown, content: {
Alert(title: Text("Headline"),
message: Text("Placeholder"),
dismissButton: Alert.Button.default(
Text("Accept"), action: {
}
)
)
})
}
}
}

Answer 1

Update: Xcode 13.4
Original variant is still valid and works "as-is", but now we can simplify code a bit with AppStorage
struct ContentView: View {
#AppStorage("FirstStart") var alertShouldBeShown = true
// ... same code
dismissButton: Alert.Button.default(
Text("Accept"), action: {
alertShouldBeShown = false
})
}
Original
Use UserDefaults to store state value.
Here is possible solution. Tested with Xcode 11.7/iOS 13.7
struct ContentView: View {
#State var alertShouldBeShown = !UserDefaults.standard.bool(forKey: "FirstStart")
var body: some View {
VStack {
Text("Hello World!")
.alert(isPresented: $alertShouldBeShown, content: {
Alert(title: Text("Headline"),
message: Text("Placeholder"),
dismissButton: Alert.Button.default(
Text("Accept"), action: {
UserDefaults.standard.set(true, forKey: "FirstStart")
}
)
)
})
}
}
}

Answer 2

import SwiftUI
struct ContentView: View {
#State private var isAlert = false
var body: some View {
Button(action: {
self.isAlert = true
}) {
Text("Click Alert")
.foregroundColor(Color.white)
}
.padding()
.background(Color.blue)
.alert(isPresented: $isAlert) { () -> Alert in
Alert(title: Text("iOSDevCenters"), message: Text("This Tutorial for SwiftUI Alert."), primaryButton: .default(Text("Okay"), action: {
print("Okay Click")
}), secondaryButton: .default(Text("Dismiss")))
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}