ios - 无法从Alamofire返回数据

Question

我想使用Alamofire调用从服务器api获取数据。但是在执行api函数之后，数据返回为空，因为Swift是异步的......

这段代码调用服务器api：

func getAllModels(completion: @escaping (_ result: [String]?) -> ()) {
    var _modelList:[String] = []
    let url = BASE_URL + "getAllProductAndModelv2"
    Alamofire.request(url, method:.get, parameters: [:], encoding: JSONEncoding.default).responseJSON { response in

        switch response.result {
        case .success:
            if((response.result.value) != nil) {
                let data = NSData(contentsOf: URL(string: url)!)
                do {
                    if let data = data, let json = try JSONSerialization.jsonObject(with: data as Data) as? [String: Any], let models = json["models"] as? [[String:Any]] {
                        for model in models {
                            if let name = model["name"] as? String {
                                _modelList.append(name)
                            }
                        }
                    }
                }catch {
                    print("error")
                }
                completion(_modelList)
            }
        case .failure(let error):
            print(error)
            completion(nil)
        }
    }
}

这段代码是从getAllModels函数获取数据：

var models:[VirtualObject] = []

    RestApiManager().getAllModels(){ (result) -> () in
        print("************************************************")
        if let result = result {
            var array = result as Array
            for item in array {
                print(item)
                models.append(VirtualObject(url: URL(string: item)!)!)
            }
        }
        print("************************************************")
    }
    print(models)
    return models

我不知道如何使用回调函数将数据绑定到return model ..请帮忙！

Answer 1

使用didSet观察变量。并在viewDidload中调用api。

class ViewController: UIViewController {

var arrModals = [Any]() {
    didSet {
        print("this call when get all modals from server")
    }
}

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    RestApiManager().getAllModels(){ (result) -> () in

        var arrTempModals = [Any]()

        if let result = result {
            var array = result as Array
            for item in array {
                print(item)
                arrTempModals.append(item)
            }
        }
        self.arrModals = arrTempModals
    }
} 

}