Swift 依赖于@Environment的init@StateObject

至少有两种方法可以使用.

1. 正如 comments 中提到的，你可以使用task或onAppear来更新你的ObservableObject.但是，这意味着该属性必须是Optional，因为它将不存在于init

class MyDataContainer: ObservableObject {
   var context: NSManagedObjectContext?
} 

struct SomeView: View {
  @Environment(\.managedObjectContext) var managedObjectContext
  @StateObject var myDataContainer = MyDataContainer()
  
  var body: some View {
     Text("Hello, world!")
       .onAppear { myDataContainer.context = managedObjectContext }
  }
}

does not需要Optionals的另一种方法是使用包装器视图.

class MyDataContrainer: ObservableObject {
  @Published var foo: [Date] = []
  
  private let context: NSManagedObjectContext
  
  init(context: NSManagedObjectContext) {
    self.context = context
    print("myDataContainer init")
  }
}

struct SomeViewWrapper: View {
  @Environment(\.managedObjectContext) var managedObjectContext

  var body: some View {
     SomeView(context: managedObjectContext)
  }
}

struct SomeView: View {
  @EnvironmentObject var router: Router
  @StateObject var weeklyStatistics: MyDataContainer
  
  init(context: NSManagedObjectContext) {
    _weeklyStatistics = StateObject(wrappedValue: StatisticsWeeklyDataContainer(context: context))
  }

  var body: some View { ... }
}

然后，当然，在以前使用SomeView的地方使用SomeViewWrapper