Alamofire 5 swift 5 等待alamofire查询结果显示初始视图

Question

目前的情况是我有登录的初始视图 (A) 和 (B) 已经登录时的第二个视图。

我希望当我打开应用程序并且用户将值存储在 UserDefaults.standard 中时，检查这些值是否与服务器的值匹配，如果它们正确则进入 B 视图。

问题是 alamofire 是异步的，在你得到答案之前就加载了 A-view。

SceneDelegate.swift

第一次尝试才知道alamofire是异步启动的

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {

   //Code to open default viewA
   ...

   //Code to try open viewB
    let logAcepted = openViewB(url, param)
    if logAcepted //<-- this execute before query in func before
     {
       if let windowScene = scene as? UIWindowScene 
        {
            let window = UIWindow(windowScene: windowScene)
             window.rootViewController = UIHostingController(rootView: Principal())
             self.window = window
             window.makeKeyAndVisible()
         }
     }
}

我看到有一个补全字段可以帮助解决这个问题，但我认为我没有很好地应用它。

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {

   //Code to open default viewA
   ...

   //Code to try open viewB
   openViewB(url, param, completion: {logAcepted in
        if logAcepted 
        {
              if let windowScene = scene as? UIWindowScene 
              {
                 let window = UIWindow(windowScene: windowScene)
                  window.rootViewController = UIHostingController(rootView: Principal())
                  self.window = window
                   window.makeKeyAndVisible()
               }
         }
      })
 }

如何使此功能运行同步？还是让主代码等待查询结果？

func openViewB(_ url: String, _ param: [String : String], completion : @escaping (Bool)->())  {
    var ret : Bool = false
    AF.request(url, parameters:  param).responseJSON {response in
        switch response.result {
            case .success(let value):
                if let JSON = value as? [String: Any]
                {
                    let status = JSON["status"] as! String
                    switch status
                    {
                        case "Ok":
                            ret =  true
                            completion(ret)
                        default:
                            ret = false
                            completion(ret)
                    }
                }
            case .failure( _):
                ret = false
                completion(ret)
        }
    }
}

我找到了很多相关信息，但是 none 在这个版本的 swift/alamofire

中有效

Answer 1

不要等待，永远不要等待。

您的 openViewB 方法已经有一个完成处理程序，请使用它。

func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {

    //Code to open default viewA
    ...

    //Code to try open viewB
    openViewB(url, param) { logAccepted in
        if logAccepted
        {
            if let windowScene = scene as? UIWindowScene 
            {
                let window = UIWindow(windowScene: windowScene)
                 window.rootViewController = UIHostingController(rootView: Principal())
                 self.window = window
                 window.makeKeyAndVisible()
             }
         }
    }
}

Alamofire 5 swift 5 等待alamofire查询结果显示初始视图

Alamofire 5 swift 5 wait for the result of the alamofire query to show the initial view

asynchronous

ios

alamofire

swift5

alamofire-request