exc_breakpoint while trying to load view in SwiftUI - xcode

Question

I'm trying to make barcode scanner app. I want the scanner to load as the app first launches, like a background. Then when a barcode is scanned, load a view on top displaying the product.
In my ContentsView() I load this View, which starts the scanner and then navigates to FoundItemSheet() when a barcode has been found.
import Foundation
import SwiftUI
import CodeScanner
struct barcodeScannerView: View {
#State var isPresentingScanner = false
#State var scannedCode: String?
#State private var isShowingScanner = false
var body: some View {
NavigationView {
if self.scannedCode != nil {
NavigationLink("Next page", destination: FoundItemSheet(scannedCode: scannedCode!), isActive: .constant(true)).hidden()
}
}
.onAppear(perform: {
self.isPresentingScanner = true
})
.sheet(isPresented: $isShowingScanner) {
self.scannerSheet
}
}
var scannerSheet : some View {
CodeScannerView(
codeTypes: [.qr],
completion: { result in
if case let .success(code) = result {
self.scannedCode = code
self.isPresentingScanner = false
}
}
)
}
}
When navigation view is replaced with a button, like this:
VStack(spacing: 10) {
if self.scannedCode != nil {
NavigationLink("Next page", destination: FoundItemSheet(scannedCode: scannedCode!), isActive: .constant(true)).hidden()
}
Button("Scan Code") {
self.isPresentingScanner = true
}
.sheet(isPresented: $isPresentingScanner) {
self.scannerSheet
}
Text("Scan a QR code to begin")
It works with this solution, but I want the scanner to show when the app loads, not on a button press. I tried replacing the button with .onAppear with the same contents as the button, but it doesn't work.
This is foundItemSheet()
struct FoundItemSheet: View {
#State private var bottomSheetShown = false
#State var scannedCode: String?
var body: some View {
GeometryReader { geometry in
BottomSheetView(
scannedCode: self.$scannedCode,
isOpen: self.$bottomSheetShown,
maxHeight: geometry.size.height * 0.7
) {
Color.blue
}
}.edgesIgnoringSafeArea(.all)
}
}
struct FoundItemSheet_Previews: PreviewProvider {
static var previews: some View {
FoundItemSheet()
}
}
I'm getting exc_breakpoint I believe where CodeScanner is declared.
I've been stuck on this for hours, so I'll reply quick to any questions.

Answer 1

Couple of thoughts..
1) change order of modifiers
.sheet(isPresented: $isShowingScanner) {
self.scannerSheet
}
.onAppear(perform: {
self.isPresentingScanner = true
})
2) make delayed sheet activation (as view hierarchy might not ready for that custom scanner view)
.onAppear(perform: {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.5)
self.isPresentingScanner = true
}
})