表仅在第二次加载后加载

Question

我在将数据加载到表格时遇到问题。在第一次点击时没有任何反应，它正在点击我的getLocations函数并且它正在完成，因为它打印（2）但表中没有显示任何内容。如果我按回然后重试，数据就在那里。我已经尝试将DispatchQueue.main.async {reload table}放在多个区域但仍然会发生。可能是我如何调用端点？昨晚我发了一篇关于它的帖子，它就在这里，它现在正在工作。这是一个愚蠢的json结构：-x Swift 4 decoding json using Codable。有没有办法预取数据？

protocol LocationListDelegate: NSObjectProtocol
{
    func sendLocationList(_ controller: LocationViewController, data: 
 [LocationList])
}

class LocationViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {

var locList: [LocationList] = []  //could this be giving me problems?

@IBOutlet weak var locationListTableView: UITableView!

weak var delegate: LocationListDelegate?

override func viewDidLoad() {
    super.viewDidLoad()
    locationListTableView.dataSource = self
    locationListTableView.delegate = self

    // call endpoint
    locList = getLocationsFromService()

//        DispatchQueue.main.async {
//            self.locationListTableView.reloadData()
//        }

}

//override func viewDidAppear(_ animated: Bool) {
//    super.viewDidAppear(animated)
//    self.locationListTableView.reloadData()
//}

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return locList.count
}

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    if let cell = locationListTableView.dequeueReusableCell(withIdentifier: "LocationCell") as? LocationsViewCell {
        let location = locList[indexPath.row]
        //print(location)
        cell.updateView(locations: location)

//            DispatchQueue.main.async {
//                self.locationListTableView.reloadData()
//            }
        return cell
    } else {
        return LocationsViewCell()
    }
}

func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
    let location = locList[indexPath.row]

    if let locDelegate = self.delegate {
        locDelegate.sendLocationList(self, data: [location])
        print(location)
        self.dismiss(animated: true, completion: nil)
    }
}

func getLocationsFromService() -> [LocationList]{
    print("1")
    return LocationService.instance.getLocations { (success) in
        if success {
            print("2")
//                DispatchQueue.main.async {
//                    self.locationListTableView.reloadData()
//                }
        }
    }
}
}

从我之前的线程更新了端点调用，该调用位于另一个swift服务文件中

func getLocations(completion: @escaping CompletionHandler) -> [LocationList] {

    let headers: HTTPHeaders = [:]

    Alamofire.request(GlobalConstants.APIURL + "/getlocationlist",
 method: .get, parameters: nil, encoding: JSONEncoding.default,
 headers: headers).responseJSON(completionHandler: { (response) in
        if response.result.error == nil {

            guard let data = response.data else { return }

            do {
                let locations = try
                    JSONDecoder().decode(Locations.self, from: data)

                self.locList = locations.data.LocationList

                //print(locList)
                completion(true)
            } catch let error {
                print(error)
                completion(false)
            }
        }
        else {
            completion(false)
            debugPrint(response.result.error as Any)
        }
    })
    return locList
}