swiftui

Hi, i’m As well looking forward to seeing the Apple best approach of the CoreData integration with SwiftUI. Anyone of you have found an Apple tutoriel or code on how to do it, properly ? Best Tim

That's.... an interesting reply.Is the slowness and stalling we experience due to APFS problems that Apple won't spend any time testing or thinking about?If Apple could fix it, every scenario of Mac use would greatly benefit, SSD or mechanical based, regardless of the application.Can you see there's a problem with promoting this new SwiftUI development model that is only practical on >$5,000 hardware?Running Apple's internal development exclusivly on hot hardware hides a multitude of sins.Only a minority of us will have fully loaded iMac or Mac Pros available for development work.Also, external SSDs have been very troublesome for us so far with Catalina's split read-only drive layout.The CPU, memory load and disk I/O aren't showing abnormally high usage, but disk traffic just mysteriously blocks very often,and when you have to split MacOS, Xcode, and a user account because it wont all fit on one drive, development is impossibly painful.Again, is this an APFS issue that will never be looked at or f

Ok, so I was being dumb.You have to pass the @State variable (with a $ specifically to identofy the reference to the State variable) to the sub-view.Maybe the error messages could be a little less arcane? Or maybe I could be less dumb !This is working:import SwiftUI import Combine struct ContentView : View { @State private var isPlaying: Bool = false var body: some View { VStack { Text(isPlaying ? Playing : Not Playing) PlayButton(isPlaying: $isPlaying) Image(systemName: isPlaying ? pause.circle : play.circle) } } } #if DEBUG struct ContentView_Previews : PreviewProvider { static var previews: some View { ContentView() } } #endif

add a 'return' statement to line 10. 'some' indicates opaque return types, so the builder has no idea what you are trying to create when you add additional logic to the declaration of the 'body' variable. To avoid the error, you either have to tell it what you actually intend to return from the closure, or, isolate your logic to functions that exist outside of the body variable declaration (and sometimes both if the compiler can't infer what you want to return). import SwiftUI struct FigureThisOut : View { @State var myColor = Color.green var body: some View { myColor = Color.red return Text(reloadCount2).color(myColor) } } #if DEBUG struct FigureThisOut_Previews : PreviewProvider { static var previews: some View { FigureThisOut() } } #endif