从嵌套的 json 文件中获取信息

Question

从网站metcheck我可以得到一个天气预报的json文件。 http://ws1.metcheck.com/ENGINE/v9_0/json.asp?lat=52.380&lon=0.060&Fc=Av

文件回来了，但我无法读取它以获取我需要的信息。我想我不明白metcheckData、forecastLocation和forecast之间的关系：

{
   "metcheckData":{
      "forecastLocation":{
         "forecast":[
            {
               "temperature":"18",
               "dewpoint":"13",
               "rain":"0.0",
               "freezinglevel":"3049",
               "uvIndex":"1",
               "totalcloud":"65",
               "lowcloud":"55",
               "medcloud":"43",
               "highcloud":"11",
               "humidity":"79",
               "windspeed":"11",
               "meansealevelpressure":"1012.77",
               "windgustspeed":"17",
               "winddirection":"249",
               "windletter":"WSW",
               "icon":"PC",
               "iconName":"Partly Cloudy",
               "chanceofrain":"0",
               "chanceofsnow":"0",
               "dayOfWeek":"4",
               "weekday":"Wednesday",
               "sunrise":"6:02",
               "sunset":"18:09",
               "cumulusBaseHeight":"540",
               "stratusBaseHeight":"549",
               "dayOrNight":"N",
               "utcTime":"2019-07-31T19:00:00.00"
            },
            {
               "temperature":"17",
               "dewpoint":"13",
               "rain":"0.1",
               "freezinglevel":"3192",
               "uvIndex":"0",
               "totalcloud":"91",
               "lowcloud":"66",
               "medcloud":"39",
               "highcloud":"35",
               "humidity":"82",
               "windspeed":"11",
               "meansealevelpressure":"1013.29",
               "windgustspeed":"17",
               "winddirection":"245",
               "windletter":"WSW",
               "icon":"RO",
               "iconName":"Intermittent Rain",
               "chanceofrain":"47",
               "chanceofsnow":"0",
               "dayOfWeek":"4",
               "weekday":"Wednesday",
               "sunrise":"6:02",
               "sunset":"18:09",
               "cumulusBaseHeight":"512",
               "stratusBaseHeight":"520",
               "dayOrNight":"N",
               "utcTime":"2019-07-31T20:00:00.00"
            }
         ],
         "continent":"",
         "country":"",
         "location":"52.4/0.1",
         "latitude":52.4,
         "longitude":0.1,
         "timezone":0
      }
      // Many other similar array entries omitted
   },
   "feedCreation":"2019-07-31T20:26:10.00",
   "feedCreator":"Metcheck.com",
   "feedModel":"GHX5",
   "feedModelRun":"00Z",
   "feedModelRunInitialTime":"2019-07-31T00:00:00.00",
   "feedResolution":"0.01"
}

使用 使用 Newtonsoft.Json； 使用 Newtonsoft.Json.Linq;

我尝试使用以下代码读取特定时间的温度预测等内容。

 JObject jo = JObject.Parse(File.ReadAllText(@"C:\temp\Weather.json", Encoding.UTF8));
 Dictionary<string, List<string>> values =
            jo.SelectToken("forecast", true).ToObject<Dictionary<string, List<string>>>();

 foreach (var kv in values)
 {
     rchtxtbx_output.AppendText(kv.Value[0] + "\r");

以此类推，认为 kv.Value[0] 将是温度，我将四处走动并获取每小时的温度。不幸的是，事实并非如此，我在

处遇到错误

Dictionary<string, List<string>> values =
                jo.SelectToken("forecast", true).ToObject<Dictionary<string, List<string>>>();

所以有些“预测”是不正确的。我也尝试过metcheckData.forecastLocation.forecast，然后是forecastLocation.forecast，但都有错误。

请告诉我如何从 json 文件中获取数据并为每个小时的预测写入富文本框。

Answer 1

您想通过其父令牌导航到所需的令牌。然后获取令牌的子列表。

JObject jo = JObject.Parse(File.ReadAllText(@"C:\temp\Weather.json", Encoding.UTF8));

// navigate to the token via its parents
List<JToken> items = jo.SelectToken("metcheckData", true).SelectToken("forecastLocation", true).SelectToken("forecast", true).Children().ToList();

foreach (JToken token in items)    
{
    string temperature = token["temperature"].Value<string>();
    string dewpoint = token["dewpoint"].Value<string>();
    // etc...
}

Answer 2

为什么不创建一个映射类并将 JSON 解析为这个对象。完成后，您可以浏览所有属性并选择所需的所有内容。

var data = JsonConvert.DeserializeObject<Rootobject>(File.ReadAllText(@"C:\temp\Weather.json", Encoding.UTF8));

public class Rootobject
{
    public Metcheckdata metcheckData { get; set; }
    public DateTime feedCreation { get; set; }
    public string feedCreator { get; set; }
    public string feedModel { get; set; }
    public string feedModelRun { get; set; }
    public DateTime feedModelRunInitialTime { get; set; }
    public string feedResolution { get; set; }
}

public class Metcheckdata
{
    public Forecastlocation forecastLocation { get; set; }
}

public class Forecastlocation
{
    public Forecast[] forecast { get; set; }
    public string continent { get; set; }
    public string country { get; set; }
    public string location { get; set; }
    public float latitude { get; set; }
    public float longitude { get; set; }
    public int timezone { get; set; }
}

public class Forecast
{
    public string temperature { get; set; }
    public string dewpoint { get; set; }
    public string rain { get; set; }
    public string freezinglevel { get; set; }
    public string uvIndex { get; set; }
    public string totalcloud { get; set; }
    public string lowcloud { get; set; }
    public string medcloud { get; set; }
    public string highcloud { get; set; }
    public string humidity { get; set; }
    public string windspeed { get; set; }
    public string meansealevelpressure { get; set; }
    public string windgustspeed { get; set; }
    public string winddirection { get; set; }
    public string windletter { get; set; }
    public string icon { get; set; }
    public string iconName { get; set; }
    public string chanceofrain { get; set; }
    public string chanceofsnow { get; set; }
    public string dayOfWeek { get; set; }
    public string weekday { get; set; }
    public string sunrise { get; set; }
    public string sunset { get; set; }
    public string cumulusBaseHeight { get; set; }
    public string stratusBaseHeight { get; set; }
    public string dayOrNight { get; set; }
    public DateTime utcTime { get; set; }
}

Answer 3

如果您从链接中获取 json 并忽略 forecast 部分，您会得到：

{
    "metcheckData": {
        "forecastLocation": {
            "forecast": [],
            "continent": "",
            "country": "",
            "location": "52.4/0.1",
            "latitude": 52.4,
            "longitude": 0.1,
            "timezone": 0
        }
    },
    "feedCreation": "2019-07-31T20:17:52.00",
    "feedCreator": "Metcheck.com",
    "feedModel": "GHX5",
    "feedModelRun": "00Z",
    "feedModelRunInitialTime": "2019-07-31T00:00:00.00",
    "feedResolution": "0.01"
}

由此，（对我而言）变得更加明显，metacheckData 和 forecastLocation 都是对象，forecast 数组是 forecastLocation 的属性。

我会做的是使用dynamics。检查this和this post

所以它可能会变成这样（未测试）：

var data = JsonConvert.DeserializeObject<dynamic>(rawJson);
var rawForecasts = data.metcheckData.forecastLocation.forecast;