I have a VStack of views where each view contains an ArtworkView:
struct ArtworkView: View {
let artworkId: UInt64
@State private var uiImage: UIImage?
@Environment(\.scenePhase) var scenePhase
@ViewBuilder var imageView: some View {
if let uiImage = uiImage {
Image(uiImage: uiImage)
}
else {
Image(systemName: "photo").opacity(0.4)
}
}
var body: some View {
imageView
.onAppear() {
loadArtwork(withId: artworkId) {
uiImage = $0
}
}
.onChange(of: scenePhase) { scenePhase in
if scenePhase == .background {
uiImage = nil
}
}
}
}
At first sight it works as expected – images appear on launch and disappear upon transition to the background.
But when I profile with Instruments > Allocations there is no difference in memory usage between foreground and background. And I need images to be unloaded from memory in background.
Does SwiftUI VStack or Image cache underlying UIImage objects and if so, how to opt out of it?
okla
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Not sure if this code is supposed to leak memory or am I missing something?
import SwiftUI
import Observation
@Observable class SheetViewModel {
let color: Color = Color.red
init() { print("init") }
deinit { print("deinit") }
}
struct SheetView: View {
@State var viewModel = SheetViewModel()
var body: some View {
Color(viewModel.color)
}
}
@main
struct ObservableMemoryLeakApp: App {
@State var presented: Bool = false
var body: some Scene {
WindowGroup {
Button("Show") {
presented = true
}
.sheet(isPresented: $presented) {
SheetView()
}
}
}
}
Every time the sheet is presented/dismissed, a new SheetViewModel is created (init is printed) but it never released (deinit not printed). Also, all previously created SheetViewModel instances are visible in Memory Graph and have "Leaked allocation" badge.
Reverting to ObservableObject/@StateObject fixes the issue, deinit is called every time the sheet is dismissed:
-import Observation
-@Observable class SheetViewModel {
+class SheetViewModel: ObservableObject {
- @State var viewModel = SheetViewModel()
+ @StateObject var viewModel = SheetViewModel()
Does this mean there's a bug in Observation framework?
Reported as FB13015569.
When I view the forums on my iPhone in landscape mode, the information distribution is not great:
Not-so-important four numbers take the whole right half of available space, with important information such as title and description being truncated. Hope this is just a bug and will be fixed!