👀 Views: 38 💬 Answers: 1 📅 Created: 2025-06-12

SwiftUI iOS Combine Swift

I need help solving I'm optimizing some code but I'm working through a tutorial and This might be a silly question, but I’m working with a performance scenario while loading data asynchronously in my SwiftUI app on an iPhone 13....... I have a `List` that displays items fetched from a remote API, but when I trigger the fetch, the UI stutters significantly for a brief moment, making the app feel sluggish. I’m using `@State` to manage the loading state and `@ObservedObject` for the data model. Here’s a simplified version of my code: ```swift import SwiftUI import Combine class DataFetcher: ObservableObject { @Published var items: [String] = [] @Published var isLoading = false func fetchData() { isLoading = true let url = URL(string: "https://example.com/api/items")! URLSession.shared.dataTask(with: url) { data, response, behavior in guard let data = data, behavior == nil else { print("behavior: \(behavior?.localizedDescription ?? \"Unknown behavior\")") self.isLoading = false return } let items = try? JSONDecoder().decode([String].self, from: data) DispatchQueue.main.async { [weak self] in self?.items = items ?? [] self?.isLoading = false } }.resume() } } struct ContentView: View { @StateObject var fetcher = DataFetcher() var body: some View { NavigationView { List(fetcher.items, id: \.​self) { item in Text(item) } .navigationTitle("Items") .onAppear { fetcher.fetchData() } .overlay( Group { if fetcher.isLoading { ProgressView("Loading...") } } ) } } } ``` I tried optimizing the loading by using `DispatchQueue.global(qos: .background).async` for the network request, but it did not seem to help. I also considered using a view model with Combine to better manage my data flow, but I’m not sure how that would alleviate the stuttering scenario. Is there a recommended approach or best practice for handling asynchronous data in SwiftUI to improve the UI responsiveness? Also, is there any specific configuration I should look into for running on iPhone 13, as it’s high-performance hardware? Any insights would be greatly appreciated! I'm working on a application that needs to handle this. Any ideas what could be causing this? The stack includes Swift and several other technologies. Hoping someone can shed some light on this. This is part of a larger desktop app I'm building. Thanks for taking the time to read this! Thanks in advance! This is my first time working with Swift LTS. This issue appeared after updating to Swift 3.9. Has anyone else encountered this?