SwiftUI MVVM如何迭代并获取数组的索引

Question

我的项目正在创建一个订购应用程序，在这个关于菜单细节的屏幕中，有一些菜单变体，用户可以选择/添加，我需要迭代[MenuDetailVariantGroup]的数组，我需要获得数组的索引，我该如何做到这一点？在for循环中，我还需要将一个变量附加到@Published var variantChosen中，但如果我执行self.viewModel.variantChosen.append(1(，它总是返回一个错误。以下是我的代码：

菜单细节数据.swift

struct MenuDetailData: Codable, Identifiable {
let id = UUID()
let idMenu: String
let menuName: String
let variantGroup: [MenuDetailVariantGroup]
}

菜单细节VariantGroup.swift

struct MenuDetailVariantGroup: Codable, Identifiable, Hashable {
let id = UUID()
let variantGroupName: String
let variant: [MenuDetailVariant]
let limit: Int
}

MenuDetailVariant.swift

struct MenuDetailVariant: Codable, Identifiable, Hashable {
let id = UUID()
let variantName: String
}

菜单细节视图Model.swift

class MenuDetailViewModel: ObservableObject, MenuDetailService {
var apiSession: APIService
@Published var detaildata: MenuDetailData?
@Published var variantGroup = [MenuDetailVariantGroup]()
@Published var variantChosen: Array<Int> = []

var cancellables = Set<AnyCancellable>()

init(apiSession: APIService = APISession()) {
self.apiSession = apiSession
}

func getMenuDetail() {
let cancellable = self.getMenuDetail()
.sink(receiveCompletion: { result in
switch result {
case .failure(let error):
print("Handle error: (error)")
case .finished:
break
}

}) { (detail) in
self.detaildata = detail.data
self.variantGroup = detail.data.variantGroup
}
cancellables.insert(cancellable)
}

}

菜单详细信息查看

struct MenuDetailView: View {
@ObservedObject var viewModel = MenuDetailViewModel()

var body: some View {
ForEach(self.viewModel.variantGroup, id: .self) { vg in
/*** I Need to get the index of each iteration here, how? ***/
VStack {
HStack {
Text(vg.variantGroupName)
Text(String(self.viewModel.arrVariantChoosen[0]))
}
VStack {
ForEach(vg.variant, id: .self) { v in
Text(v.variantName)
}
}
}
// I also need to append Int to @Published var variantChosen
self.viewModel.variantChosen.append(1)
// This always return error:
// Type '()' cannot conform to 'View'; only struct/enum/class types can conform to protocols
}
}
}
}

这是我迄今为止尝试过但失败并返回空的代码

// This returns blank
ForEach(0..<self.viewModel.variantGroup.count) { i in
Text("(self.viewModel.variantGroup[i].variantGroupName)")
}
// This too returns blank
ForEach(self.viewModel.variantGroup.indices) { i in
Text("(self.viewModel.variantGroup[i].variantGroupName)")
}

提前感谢大家

Answer 1

您可以使用枚举来同时拥有索引和元素，如

var body: some View {
ForEach(Array(self.viewModel.variantGroup.enumerated()), id: .1) { index, vg in
/*** I Need to get the index of each iteration here, how? ***/
VStack {