我认为你的代码破坏了MVVM，因为你向视图公开了一个存储模型。在MVVM中，你的ViewModel应该只包含两个东西：
1.您的视图应显示的值。这些值应使用绑定系统（在您的情况下为合并）自动更新。
1.视图可能产生的事件（在你的例子中，一个按钮点击）记住这一点，你的ViewModel应该Package，适配和封装你的模型。我们不希望模型的改变影响视图。这是一个干净的方法：查看方式：

struct ContentView: View {

    @StateObject // When the view creates the object, it must be a state object, or else it'll be recreated every time the view is recreated
    private var viewModel = ViewModel()

    var body: some View {
        VStack {
            Text("\(viewModel.currentNumber)") // We don't want to use functions here, as that will create a new object , as SwiftUI needs the same reference in order to keep track of changes
                .padding()
            Button("IncreaseNumber") {
                viewModel.increaseNumber()
            }
        }
    }
}

struct ContentView_Previews: PreviewProvider {
    static var previews: some View {
        ContentView()
    }
}

视图模型：

class ViewModel: ObservableObject {

    @Published
    private(set) var currentNumber: Int = 0 // Private set indicates this should only be mutated by the viewmodel
    private let numberStorage = NumberStorage()

    init() {
        numberStorage.currentNumber
            .map { $0.number }
        .assign(to: &$currentNumber) // Here we're binding the current number on the storage to the published var that the view is listening to.`&$` basically assigns it to the publishers address
    }

    func increaseNumber() {
        self.numberStorage.increaseNumber()
    }
}

产品型号：

class NumberStorage {
    private let currentNumberSubject = CurrentValueSubject<NumberObject, Never>(NumberObject())

    var currentNumber: AnyPublisher<NumberObject, Never> {
        currentNumberSubject.eraseToAnyPublisher()
    }

   func increaseNumber() {
       let currentNumber = currentNumberSubject.value.number
       currentNumberSubject.send(.init(number: currentNumber + 1))
    }
}

struct NumberObject: Identifiable { // I'd not use this, just send and int directly
    let id = UUID()
    var number = 0
}

这是一个简单的问题。SwiftUI还不支持嵌套的可观察对象。我认为这里不需要ViewModel+Model，因为ViewModel似乎就足够了。
要实现这一点，您必须在触发模型的objectWillChange时手动触发viewModel的objectWillChange：

class ViewModel: ObservableObject {
    init() {
        number.objectWillChange.sink { [weak self] (_) in
            self?.objectWillChange.send()
        }.store(in: &cancellables)
    }
}

加：
由于不是注入，而是在视图中初始化viewModel，所以最好使用StateObject而不是ObservedObject。请参阅Apple文档中的参考：Managing model data in your app

处理这个问题的一种方法是观察Storage类中的发布者，并在objectWillChange发布者发生变化时发送它。我在个人项目中通过添加一个类来实现这一点，我的所有视图模型都从这个类继承，它提供了一个很好的接口，并像这样处理合并的东西：

父视图模型

import Combine

class ViewModel: ObservableObject {
    private var cancellables: Set<AnyCancellable> = []

    func publish<T>(on publisher: Published<T>.Publisher) {
        publisher.sink { [weak self] _ in self?.objectWillChange.send() }
            .store(in: &cancellables)
    }
}

特定视图模型

class ContentViewModel: ViewModel {
    private let numberStorage = NumberStorage()

    var number: Int { numberStorage.numberObject.number }

    override init() {
        super.init()
        publish(on: numberStorage.$numberObject)
    }

    func increaseNumber() {
        numberStorage.increaseNumber()
    }
}

检视

struct ContentView: View {
    @StateObject var viewModel = ContentViewModel()

    var body: some View {
        VStack {
            Text("\(viewModel.number)")
                .padding()
            Button("IncreaseNumber") {
                viewModel.increaseNumber()
            }
        }
    }
}

型号/存储

class NumberStorage:ObservableObject {
    @Published var numberObject: NumberObject

    init() {
        numberObject = NumberObject()
    }

    public func increaseNumber() {
        self.numberObject.number += 1
    }
}

struct NumberObject: Identifiable {
    let id = UUID()
    var number = 0
}

这会导致每次Storage.numberObject更改时视图都会重新呈现。