Question

这是我想在下载所有细节后执行的功能，以及下载后更新UIElements的另一个功能。此功能位于＆＃34; CurrentWeather.swift＆＃34;

内

func downloadWeatherDetails(completed: ( () -> () )){
    // tell Alimofire where to download
    let currentWeatherURL = URL(string: CURRENT_WEATHER_URL)!
    Alamofire.request(currentWeatherURL).responseJSON{ response in

        let result = response.result
        if let dict  = result.value as? Dictionary<String, AnyObject>{

            if let name = dict["name"] as? String{
                self._cityName = name.capitalized
                print(self._cityName)
            }

            if let weather = dict["weather"] as? [Dictionary<String, AnyObject>]{
                if let main = weather[0]["main"] as? String{
                    self._weatherType = main.capitalized
                    print(self._weatherType)
                }
            }

            if let main = dict["main"] as? Dictionary<String, AnyObject>{
                if let currentTemperature = main["temp"] as? Double {
                    let kelvinToFarenhitePreDevision = (currentTemperature * (9/5) - 459.67 )
                    let kelvinToFarenhite = Double(round(10 * kelvinToFarenhitePreDevision/10))
                    self._currentTemp = kelvinToFarenhite
                    print(self._currentTemp)
                }
            }


        }


    }
    completed()
}

}

此功能是更新UIEmelents

    func updateMainUI(){

    dateLabel.text = currentWeather.date
    currentTempLabel.text = "\(currentWeather.currentTemp)"
    currentWeatherTypeLabel.text = currentWeather.weatherType
    locationLabel.text = currentWeather.cityName
    currentWeatherImage.image = UIImage(named: currentWeather.weatherType)
}

这是在Override func viewDidLoad（）

上调用它们

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

    currentWeather.downloadWeatherDetails { () -> () in 
        self.updateMainUI()
    }
}

现在当我执行它不更新UI数据时但它在控制台内打印

任何人都可以帮我解决这个问题

Answer 1

您在请求完成前致电completed()。

        completed() //<- you need to call the completion handler inside the closure.
    }
    //completed() //<- this would be called before completion
}

我没有检查过代码的其他部分，但至少你需要解决这个问题。

Answer 2

您的weatherDetails将异步下载。在viewDidLoad（）内部，在收到并解析响应之前调用self.updateMainUI（）。所以只需将UIUpdateMainUI（）方法放在此块的末尾和内部：

if let dict  = result.value as? Dictionary<String, AnyObject>{
}

如果您要求其他班级，请在那里设计协议。在要更新的viewController中对其进行符合。从上面的if-let块开始，在解析结束时，调用viewController的delegate方法进行更新。当然，在委托方法中，更新您的UI。感谢。

函数运行后执行函数swift 3

2 个答案: