Mvvm ViewModel Async Func完成时如何从子视图更新EnvironmentObject

在我的SwiftUI应用程序中，我有一个入口点，如下所示

@main
struct SomeApp: App {
    @UIApplicationDelegateAdaptor(AppDelegate.self) var appDelegate
    var body: some Scene {
        WindowGroup {
            AppContainerView()
        }
    }
}

我可以像这样更新

isLoggedIn

class AppState: ObservableObject {
    var cancellables: [AnyCancellable] = []
    private let userService: UserServiceProtocol
    init(userService: UserServiceProtocol = UserService()) {
        self.userService = userService
        subscribeForAuthChanges()
    }
    
    func subscribeForAuthChanges() {
        userService.authChangeSubject.sink(receiveValue: { [weak self] auth, user in
            print(auth)
            if user != nil {
                self?.isLoggedIn = true
            }
        }).store(in: &cancellables)
    }
    
    @Published var isLoggedIn = false
    @Published var hasSeenOnboarding = false
}

但是当涉及到

hasSeenOnboarding

时，需要在

LandingView

子视图之一的viewModel中完成某个网络调用后将其设置为true。我可以这样做

struct ChildView: View {
  @EnvironmentObject var appState: AppState
  @StateObject var viewModel = ChildViewModel()

  var body: some View {
    VStack {
      //...
    }.onReceive($viewModel.networkCallCompleted) { completed in
       self.appState.hasSeenOnboarding = completed
    }
  }
}

---

但这感觉不对……在使用MVVM时，有没有更好的选项可以从childView/viewModel更改appState？或者更好的方法？

一种可能的替代方法是将

AppState

传递给

ChildViewModel

，并直接在视图模型中执行

AppState

更新

struct ParentView: View {
  @EnvironmentObject var appState: AppState

  var body: some View {
    ChildView(viewModel: ChildViewModel(appState: appState))
  }
}

---

注意

---

您可能需要查看依赖项注入以使其更干净。下面是一个可能的示例：.

感谢这一点-尽管当我将@Published hasSeenOnboarding属性更改为@AppStorage（AppState.hasSeenOnboardingKey）var hasSeenOnboarding:Bool=false时，它不会为某些用户重新加载视图reason@jeh

@AppStorage

应仅在视图中使用（就像

@State

）。

struct ParentView: View {
  @EnvironmentObject var appState: AppState

  var body: some View {
    ChildView(viewModel: ChildViewModel(appState: appState))
  }
}

struct ChildView: View {
  @EnvironmentObject var appState: AppState
  @StateObject var viewModel: ChildViewModel

  var body: some View {
    ...
  }
}