我在导航视图层次结构上遇到了问题。
我的应用程序中所有的屏幕都使用相同的ViewModel。
当导航链接内的屏幕更新ViewModel(这里称为DataManager)时,导航视图会自动返回到第一个屏幕,就像按下“返回”按钮一样。
我尽可能地精简了我的代码。
struct DataModel: Identifiable, Codable {
var name: String
var isPinned: Bool = false
var id: String = UUID().uuidString
}
class DataManager: ObservableObject {
@Published private(set) var allModules: [DataModel]
var pinnedModules: [DataModel] {
allModules.filter { $0.isPinned }
}
var otherModules: [DataModel] {
allModules.filter { !$0.isPinned }
}
func pinModule(id: String) {
if let moduleIndex = allModules.firstIndex(where: { $0.id == id }) {
allModules[moduleIndex].isPinned = true
}
}
func unpinModule(id: String) {
if let moduleIndex = allModules.firstIndex(where: { $0.id == id }) {
allModules[moduleIndex].isPinned = false
}
}
static let instance = DataManager()
fileprivate init() {
allModules =
[DataModel(name: "One"),
DataModel(name: "Two"),
DataModel(name: "Three"),
DataModel(name: "Four"),
DataModel(name: "Five")]
}
}
struct ModulesList: View {
@StateObject private var dataStorage = DataManager.instance
var body: some View {
NavigationView {
List {
Section("Pinned") {
ForEach(dataStorage.pinnedModules) { module in
ModulesListCell(module: module)
}
}
Section("Other") {
ForEach(dataStorage.otherModules) { module in
ModulesListCell(module: module)
}
}
}
}
}
fileprivate struct ModulesListCell: View {
let module: DataModel
var body: some View {
NavigationLink {
SingleModuleScreen(module: module)
} label: {
Text(module.name)
}
}
}
}
struct SingleModuleScreen: View {
@State var module: DataModel
@StateObject var dataStorage = DataManager.instance
var body: some View {
HStack {
VStack(alignment: .leading) {
Text(module.name)
.font(.title)
Button {
dataStorage.pinModule(id: module.id)
} label: {
Text("Pin")
}
}
}
}
}