Question

我正在做一个JSON请求，我在整个应用程序中做了同样的事情。但不知何故，在这种特殊情况下，它根本没有任何错误。

这就是我调用JSON的方式，我放置了应该在控制台中显示的2 prints。第一个做，第二个做任务。

let url = URL(string: "http://api.openweathermap.org/data/2.5/forecast/daily?q=\(cityName),PL&mode=json&units=metric&cnt=5&appid=e9f269***")
var request = NSMutableURLRequest(url: url! as URL, cachePolicy: NSURLRequest.CachePolicy.returnCacheDataElseLoad, timeoutInterval: Double.infinity)

if Reachability.isConnectedToNetwork(){
    request = NSMutableURLRequest(url: url! as URL, cachePolicy: NSURLRequest.CachePolicy.useProtocolCachePolicy, timeoutInterval: Double.infinity);
}

let session = URLSession.shared

print("This does get returned in the console")

let task = session.dataTask(with: request as URLRequest,
                            completionHandler: { data, response, error -> Void in
                                do {
                                    if let json = try JSONSerialization.jsonObject(with: data!) as? [[String: String]] {

                                        print("This is not returned in the console")

                                        for weerData in json {
                                            self.weerItemsDag.append(DailyWeatherItem(dictionary:weerData as NSDictionary)!)
                                        }

                                        //Retrieved JSON

                                        //Get daily weather items
                                        self.getDailyWeatherItems(cityName: cityName)

                                    }
                                } catch { print(error) }
})
task.resume()

示例JSON：

{  
   "city":{  
      "id":3099434,
      "name":"Gdansk",
      "coord":{  
         "lon":18.6464,
         "lat":54.3521
      },
      "country":"PL",
      "population":461865
   },
   "cod":"200",
   "message":0.516424,
   "cnt":5,
   "list":[  
      {  
         "dt":1515146400,
         "temp":{  
            "day":5,
            "min":4.38,
            "max":5.21,
            "night":4.5,
            "eve":4.91,
            "morn":5
         },
         "pressure":997.38,
         "humidity":96,
         "weather":[  
            {  
               "id":500,
               "main":"Rain",
               "description":"light rain",
               "icon":"10d"
            }
         ],
         "speed":10.02,
         "deg":246,
         "clouds":64,
         "rain":1.27
      },
      {  
         "dt":1515232800,
         "temp":{  
            "day":4.45,
            "min":3.19,
            "max":4.83,
            "night":3.19,
            "eve":4.68,
            "morn":4.05
         },
         "pressure":1012.94,
         "humidity":100,
         "weather":[  
            {  
               "id":800,
               "main":"Clear",
               "description":"sky is clear",
               "icon":"01d"
            }
         ],
         "speed":5.9,
         "deg":271,
         "clouds":88,
         "rain":0.69
      },
      {  
         "dt":1515319200,
         "temp":{  
            "day":2.18,
            "min":1.06,
            "max":2.5,
            "night":1.62,
            "eve":1.71,
            "morn":1.73
         },
         "pressure":1034.07,
         "humidity":100,
         "weather":[  
            {  
               "id":800,
               "main":"Clear",
               "description":"sky is clear",
               "icon":"01d"
            }
         ],
         "speed":5.71,
         "deg":331,
         "clouds":0
      },
      {  
         "dt":1515405600,
         "temp":{  
            "day":2.57,
            "min":0.8,
            "max":3.94,
            "night":0.84,
            "eve":2.04,
            "morn":3.94
         },
         "pressure":1043.75,
         "humidity":97,
         "weather":[  
            {  
               "id":800,
               "main":"Clear",
               "description":"sky is clear",
               "icon":"01d"
            }
         ],
         "speed":4.45,
         "deg":341,
         "clouds":0,
         "snow":0.01
      },
      {  
         "dt":1515492000,
         "temp":{  
            "day":1.52,
            "min":-2.57,
            "max":1.52,
            "night":0.3,
            "eve":-0.6,
            "morn":-2.57
         },
         "pressure":1037.52,
         "humidity":0,
         "weather":[  
            {  
               "id":800,
               "main":"Clear",
               "description":"sky is clear",
               "icon":"01d"
            }
         ],
         "speed":3.36,
         "deg":280,
         "clouds":0,
         "snow":0.02
      }
   ]
}

Answer 1

请阅读JSON，{}是字典，[]是数组，所以根对象显然是字典

if let json = try JSONSerialization.jsonObject(with: data!) as? [String: Any],
   let list = json["list"] as? [[String:Any]] { 
       for weerData in list { 
       ...

JSON中根本没有[[String:String]]数组。

并且不要在Swift中使用NSDictionary和NS(Mutable)URLRequest

JSON请求什么都不做

1 个答案: