问为什么在我的ViewModel应用程序中添加了一个SwiftUI之后，我的UI没有更新呢？

EN

import Foundation
import SwiftUI
import Combine

struct Tournament: Identifiable {
    var id = UUID().uuidString
    var name: String
    var location: String = "Franchises"
    var date: Date = Date()
}

#if DEBUG
var blankTournament = Tournament(name: "")
var testTournamentData = [
    Tournament(name: "Tournament 1"),
    Tournament(name: "Tournament 2"),
    Tournament(name: "Tournament 3"),
]
#endif

struct ContentView: View {
    @ObservedObject var tournamentListVM = TournamentListVM()

    var body: some View {
        NavigationView {
            VStack {
                List(tournamentListVM.tournamentCellVMs) { tournamentCellVM  in
                    NavigationLink(
                        destination: TournamentDetails(tournament: tournamentCellVM.tournament),
                        label: { TournamentCell(tournamentCellVM: tournamentCellVM) }
)}}
            .navigationTitle("All in Two (\(tournamentListVM.tournamentCellVMs.count))")
            .navigationBarItems(
                trailing: NavigationLink(
                    destination: TournamentDetails(addingNewTournament: true))
                        { Image(systemName: "plus") }
)}}}

struct TournamentCell: View {
    @ObservedObject var tournamentCellVM: TournamentCellVM

    var body: some View {
        VStack(alignment: .leading) {
            Text(tournamentCellVM.tournament.name)
        }
    }
}

struct TournamentDetails: View {
    @Environment(\.presentationMode) var presentationMode // used to dismiss the view
    @ObservedObject var tournamentListVM = TournamentListVM()

    @State var tournament = blankTournament

    var addingNewTournament: Bool = false
    var index: Int? // needed when updating an existing record

    var body: some View {
        Form {
            Section(header: Text("Tournament Info")) {
                TextField("Name", text: $tournament.name)
                TextField("Location", text: $tournament.location)
                DatePicker(selection: $tournament.date, displayedComponents: .date) { Text("Date") }
            }
            Section { Button(action: {
                if addingNewTournament  { tournamentListVM.createTournament(tournament) }
                else                            { tournamentListVM.updateTournament(tournament) }
                presentationMode.wrappedValue.dismiss()
            }) { Text(addingNewTournament ? "Save Tournament" : "Update Tournament") }
}}}}

class TournamentListVM: ObservableObject {
    @Published var tournamentCellVMs = [TournamentCellVM]()

    private var cancellables = Set<AnyCancellable>()

    init() {
        self.tournamentCellVMs = testTournamentData.map { tournament in
            TournamentCellVM(tournament: tournament)
        }
    }

    func createTournament(_ tournament: Tournament) {
        print (tournamentCellVMs.count)
        tournamentCellVMs.append(TournamentCellVM(tournament: tournament))
        print (tournamentCellVMs.count)
    }

    func updateTournament(_ tournament: Tournament) {
    }
}

class TournamentCellVM: ObservableObject, Identifiable {
    @Published var tournament: Tournament

    var id = ""

    private var cancellables = Set<AnyCancellable>()

    init(tournament: Tournament) {
        self.tournament = tournament

        $tournament
            .map { tournament in tournament.id }
            .assign(to: \.id, on: self)
            .store(in: &cancellables)
}}