SwiftUI:无法绑定到Picker中结构中的对象

我正在创建一个可重用的TestView，但无法将结构的属性绑定到选择器。在本例中，我试图绑定到@State对象

其思想是从

jobListViewModel

提供的频道列表中选择一个频道

代码：

---

但是，从选择器中选择任何通道后，选择器不会显示选定的通道。如何将通道从

jobListViewModel

绑定到选择器？

通常，嵌套的

observeObject

s可能会有问题。我还将考虑使用

Picker

而不是整个对象来存储您选择的频道的

id

struct TestObject: Codable, Identifiable {
    @DocumentID var id = UUID().uuidString
    var channel: Channel?
}


struct Channel: Codable, Identifiable, Hashable {
    @DocumentID var id = UUID().uuidString
    var name: String
}

struct TestView: View {
    var jobListViewModel: JobListViewModel
    @State var testObject: TestObject
    
    var body: some View {

        NavigationView {
            Form {
                Section() {
                    Picker("Post to", selection: $testObject.channel) {
                        ForEach(jobListViewModel.channelViewModels, id: \.id) { (vm) in
                            Text(vm.channel.name)
                        }
                    }
                }
            }
        }
    }
}

class JobListViewModel: ObservableObject {

    //Channels
    @Published var channelsRepository = ChannelsRepository()
    @Published var channelViewModels = [ChannelViewModel]()
    
    private var cancellables = Set<AnyCancellable>()
    
    init() {   
        channelsRepository.$channels
            .map { (channels) in
                channels.map {ChannelViewModel(channel: $0)}
            }
            .assign(to: \.channelViewModels, on: self)
            .store(in: &cancellables)
    }
}

class ChannelViewModel: ObservableObject, Identifiable {
    @Published var channel: Channel
    
    var id = ""
    private var cancellables = Set<AnyCancellable>()
    
    init(channel: Channel) {
        self.channel = channel
        
        $channel
            .compactMap { (channel) in
                channel.id
            }
            .assign(to: \.id, on: self)
            .store(in: &cancellables)
    }
}

//In ContentView
    .sheet(item: $activeSheet) { (sheet) in
        switch sheet {
            case .testSheet:
                let testObject = TestObject(channel: jobListViewModel.channelViewModels.first?.channel)
                TestView(jobListViewModel: jobListViewModel, testObject: testObject)
                
        }
    }