swift alamofire返回值为空 [英] swift alamofire return value is empty

问题描述

我有以下方法：

    func getAlamoPlayers() ->[Player]{


    //Get TeamID
    let prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
    var TeamId:String = prefs.stringForKey("TEAMID")!

    //create parameters for POST
    let parameters =
    ["IdTeam": TeamId]

    var result: NSArray?

    //Request
    Alamofire.request(.POST, "XXXXXX.php", parameters: parameters)

        .responseJSON { (request, response, json, error) -> Void in

            result = (json as NSArray)
            // Make models from Json data
            for (var i = 0; i < result?.count; i++) {
                let dic: NSDictionary = result![i] as NSDictionary
                //Create a team object
                var p:Player = Player()

                //Assign the values of each key value pair to the team object
                p.PlayerID    = dic["IdPlayer"] as String
                p.PlayerName  = dic["name"] as String
                p.PlayerFkToTeam = dic["teams_IdTeam"] as String

                //Add the team to the player array
                self.players.append(p)

            }

    }

    return self.players
}

因此，当我在另一个类中调用此方法时，players数组为空！如何处理alamofire的异步请求？我认为该方法会在请求完成之前返回玩家对象，还是我错了？

So when i call this method in another class the players array is empty! How can I handle the asynchronous request of alamofire? I think the method returns the player object before the request is finished, or am I wrong?

谢谢！

推荐答案

这是一个与您基本相同的问题。

Here is a question that asks basically the same thing you are.

AlamoFire GET api请求未按预期工作

所以基本上发生的是您的发帖请求在后台队列中被调用。因此，将其视为致电您的帖子，然后继续进行下一行。因此，由于它位于后台线程中，因此直到函数返回后才设置变量。

So basically what is happening is that your post request is being called in a background queue. So think of it as calling your post then continuing on to the next line. So since it is in a background thread it doesn't set the variable till after your function returns.

您可以使用完成处理程序，如链接I中详细说明的那样提供。另一个解决方案是使用NSNotificationCenter。设置观察者，然后在POST请求中发布通知。

You could use a completion handler as explained in detail in the link I provided. Another solution would be to use NSNotificationCenter. Set up an observer and then post a notification inside your POST request.

因此，例如：
首先在类的顶部声明您的通知名称，您将在其中使用帖子响应功能。以便其他班级可以访问它

So for example: First declare your notification name at the top of the class where you will have your post response function as so. So that other classes can access it

让YOUR_NOTIFICATION_NAME = NOTIFICATION NAME
班级YOUR_CLASS {

然后在类内部编写您要在POST完成后执行的代码。

then inside the class write the code you want to execute once the POST is done.

func YOUR_FUNCTION {
...
}

然后在执行POST请求之前要添加

Then before you execute your POST request you want to add an observer.

NSNotificationCenter.defaultCenter（）。addObserver（自身，选择器： YOUR_FUNCTION，名称：YOUR_NOTIFICATION_NAME，对象：nil）

然后在POST请求中发布通知。

Then post your notification inside your POST request.

Alamofire.request(.POST, "XXXXXX.php", parameters: parameters)
    .responseJSON { (request, response, json, error) -> Void in
         ...<your code>...
   self.players.append(p)
   NSNotificationCenter.defaultCenter().postNotificationName(YOUR_NOTIFICATION_NAME, object: self)
}

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