如何在异步调用SwfitUI之后加载初始屏幕

问题描述

在AppDelegate类中，我正在调用Auth API，它返回令牌。然后在UserDefaults中设置令牌。 但是，此时我的HomeView也正在打开，其.onAppear {}函数正在调用另一个api。我想等待Auth API结果的完成。之后要打开HomeView。我该怎么办？

这也是授权或获取令牌的正确方法吗？

这是我的AppDelegate，Service和HomeView：

class AppDelegate: UIResponder,UIApplicationDelegate {
    func application(_ application: UIApplication,didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        Service.shared.authorize(userName: "username",password: "password") { (response) in
            UserDefaults.standard.set(response.token,forKey: "Token")     
        } 
        return true
    }

class Service {
   func authorize(userName: String,password: String,completion: @escaping(AuthResponse>) -> ()) {
        // Here I'm calling auth api
        callApiAsync(urlRequest: urlRequest) { (apiResponse) in
            completion(apiResponse)
        }
    }
}

struct HomeView: View {
    @Observedobject var vm = Homeviewmodel()
    var body: some View {
        Text("HomeView")
        .onAppear {
            self.vm.getList() { response in
                
            }
        }
    }
}

解决方法

我不知道您在哪里初始化UIWindow。 AppDelegate / SceneDelegate
我为SceneDelegate但AppDelegate制作的样本与此类似。

在请求完成后初始化窗口。

func scene(_ scene: UIScene,willConnectTo session: UISceneSession,options connectionOptions: UIScene.ConnectionOptions) {
    Service.shared.authorize(userName: "username",password: "password") { (response) in
        UserDefaults.standard.set(response.token,forKey: "Token")     
        if let windowScene = scene as? UIWindowScene {
            let window = UIWindow(windowScene: windowScene)
            window.rootViewController = UIHostingController(rootView: HomeView())
            self.window = window
            window.makeKeyAndVisible()
        }
    } 
}