SwiftUI 在 observedObject 更改时没有更新视图

Question

我正在做一个登录和显示数据的应用程序。当用户登录时，数据将正确显示。当我注销并登录另一个帐户时，数据应该由调用函数以重新加载数据的 observedObject 更新。但是当我登录到应用程序时，主页视图仍然显示以前帐户的旧数据。我不知道是什么问题。我尝试了很多方法来解决，即使我在注销时清除 class 中的数据，但是，视图仍然没有更新。寻求帮助，谢谢。

struct ContentView: View {
    @EnvironmentObject var authService:AuthService
    var body: some View{
        ZStack{
            if(!authService.signedIn){
                RegisterView()
            }
            else{
                HomePageView()
            }
        }
    }}

struct HomePageView: View {
    @ObservedObject var shopList:ShopJSON = .shared

    var body: some View {
        
        TabView{
            HomePromotionView(shopList: shopList)
                .tabItem {
                        Image(systemName: "house")
                }.tag(1)

            NavigationView{
                BookingView()
            }
                .tabItem {
                    Image(systemName: "calendar")
                }.tag(3)
        }
        .onAppear(perform: ShopJSON.shared.reload) //I try to force reload data.
    }
}

struct HomePromotionView: View {
    @State private var selectedSegment = 0
    @ObservedObject var shopList : ShopJSON

    private let homeSegment = ["PROMOTION", "HISTORY", "MESSAGE"]
    
    var body: some View {
        NavigationView {
            
            VStack {
                ScrollView(.horizontal, showsIndicators: false){
                    
                    HStack{
                        
                        ForEach(shopList.shops){ item in
                            MerchantBar(name:item.name!, icon: item.icon!, id: item.shopID!)
                        }

class ShopJSON: ObservableObject {
    
    @Published var shops = [Shops]()
    @Published var bcsts = [Bcast]()
    @Published var selectedID : Int?
    static let shared = ShopJSON()

    let auth = UserDefaults.standard.string(forKey: "Auth")
    
    private init() {
        load()
    }
    func reload() {
        load()
    }
    func clear() {
        self.shops = [Shops]()
        self.bcsts = [Bcast]()
        self.selectedID = nil
    }
    func load() {
        
        let url = URL(string: "https://12345/shop/")!
        var request = URLRequest(url: url)
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.setValue(self.auth, forHTTPHeaderField: "token")
        request.httpMethod = "GET"
        
        URLSession.shared.dataTask(with: request) { data, response, error in
            guard let data = data else {
                print("No data in response: \(error?.localizedDescription ?? "Unknown error").")
                return
            }
            if let decodedShops = try? JSONDecoder().decode(Json4Swift_Base.self, from: data) {
                DispatchQueue.main.async {
                    self.shops = decodedShops.shops!
                    self.bcsts = decodedShops.bcast!

注销按钮

            Text("Sign Out")
                .foregroundColor(Color.gray)
                .onTapGesture {
                    self.authService.signOut()
                    UserDefaults.standard.set(nil, forKey: "Auth")
                    //self.shopList.clear()       //force clean data but view didn't update while login with another account
            }

Answer 1

我发现了同样的问题，并通过使用 EnvironmentObjects 而不是 ObservedObjects 解决了这个问题。在数据封装方面不太理想，但它对我有用。

Answer 2

问题是我在 class 中声明了授权令牌。当用户注销时，class 中的令牌没有更新。它仍然会使用旧令牌来获取结果。

解决方案是在函数中获取令牌而不是在 class

中声明

解决方案：

func load() {
        let url = URL(string: "https://12345/shop/")!
        var request = URLRequest(url: url)
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        let auth = UserDefaults.standard.string(forKey: "Auth")
        request.setValue(auth, forHTTPHeaderField: "token")
        request.httpMethod = "GET"

SwiftUI 在 observedObject 更改时没有更新视图

SwiftUI didn't update the view while observedObject changed

swiftui

observedobject

zstack