ios - 无法从 Dark Sky API 获取数据

Question

我尝试从 Dark Sky API 获取有关每小时天气的信息，但代码在 if let data = hourly["data"] as? [String : AnyObject] 行(在每行之后检查打印内容)。我想知道我的代码有什么问题。我认为这可能与“数据”有关，但我不确定。

 let Task2 = URLSession.shared.dataTask(with: urlRequestDark) { (data, response, error) in
        if error == nil {
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as! [String : AnyObject]

                if let hourly = json["hourly"] as? [String : AnyObject] {
                    if let data = hourly["data"] as? [String : AnyObject]{


                        if let hourNum = data["14"] as? [String : AnyObject] {
                            if let chanceRain = hourNum["precipProbability"] as? Float{
                                self.chanceHour1 = String(chanceRain)
                            }
                            DispatchQueue.main.sync {
                                self.ChanceRainLabel.text = self.chanceHour1
                            }
                        }
                    }

                }

            } catch let jsonError {
                print(jsonError.localizedDescription)
            }
        }
    }
    Task2.resume() test

奇怪的是，这确实有效:

let urlRequestDark = URLRequest(url: URL (string: "https://api.darksky.net/forecast/(API Key)/(coordinates)")!)

    let Task = URLSession.shared.dataTask(with: urlRequestDark) { (data, response, error) in
        if error == nil {
            do{
                let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as! [String : AnyObject]


                if let currently = json["currently"] as? [String : AnyObject] {

                    if let chance2 = currently["precipProbability"] as? Float{
                        print(String(chance2))
                        self.chance = String(Int(chance2 * 100)) + "%"
                        self.PreType = currently["precipType"] as? String
                    }

                        if let _ = json["error"]{
                    }

                    DispatchQueue.main.sync{
                        self.TypeLabel.text = self.PreType
                        self.ChanceLabel.text = self.chance
                    }
                }


            }catch let jsonError{
                print(jsonError.localizedDescription)
            }
        }
    }
    Task.resume()

Answer 1

你犯了几个错误。

首先，"data" 是一个字典数组，所以它应该被转换为 [[String : AnyObject]]。

其次，您正在尝试通过 String 而不是 Int 为数组下标。

第三，在转义闭包中使用 self 可能会产生保留循环。

让我向您推荐一些固定和调整后的代码。

let task2 = URLSession.shared.dataTask(with: urlRequestDark) { [weak self] (data, response, error) in
    guard error == nil else { return }
    do {
        if let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? [String : AnyObject],
            let hourly = json["hourly"] as? [String : AnyObject],
            let data = hourly["data"] as? [[String : AnyObject]],
            data.count > 14,
            let chanceRain = data[14]["precipProbability"] as? Float {
                self?.chanceHour1 = String(chanceRain)
                DispatchQueue.main.sync {
                    self?.ChanceRainLabel.text = self?.chanceHour1
                }
        }
    } catch let jsonError {
        print(jsonError.localizedDescription)
    }
}
task2.resume()