使用 C# - ASP.NET Core MVC 反序列化 API Json 时出错

Question

我正在尝试调用 API 并反序列化输出的 json。单击我的视图时出现以下错误：

JsonSerializationException: Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List`1[MvcSpatial.Models.Weather+Root]' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly.
To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object. Path 'type', line 2, position 9.*

我认为我正在使用 IEnumerable，但我不知道这是否是问题的原因。有什么想法吗？

这是我的类使用 https://json2csharp.com/

public class weather 
{
    public class Symbol
    {
        [JsonProperty("value")]
        public string Value { get; set; }

        [JsonProperty("type")]
        public string Type { get; set; }
    }

    public class Unit
    {
        [JsonProperty("label")]
        public string Label { get; set; }

        [JsonProperty("symbol")]
        public Symbol Symbol { get; set; }
    }

    public class ObservedProperty
    {
        [JsonProperty("id")]
        public string Id { get; set; }

        [JsonProperty("label")]
        public string Label { get; set; }
    }

    public class MeasurementType
    {
        [JsonProperty("method")]
        public string Method { get; set; }

        [JsonProperty("period")]
        public string Period { get; set; }
    }

    public class DewPoint
    {
        [JsonProperty("type")]
        public string Type { get; set; }

        [JsonProperty("description")]
        public string Description { get; set; }

        [JsonProperty("unit")]
        public Unit Unit { get; set; }

        [JsonProperty("observedProperty")]
        public ObservedProperty ObservedProperty { get; set; }

        [JsonProperty("measurementType")]
        public MeasurementType MeasurementType { get; set; }
    }

    public class Parameters
    {
        [JsonProperty("Dew point")]
        public DewPoint DewPoint { get; set; }
    }

    public class Properties
    {
        [JsonProperty("name")]
        public string Name { get; set; }

        [JsonProperty("Dew point")]
        public List<int> DewPoint { get; set; }

        [JsonProperty("time")]
        public List<DateTime> Time { get; set; }
    }

    public class Geometry
    {
        [JsonProperty("type")]
        public string Type { get; set; }

        [JsonProperty("coordinates")]
        public List<double> Coordinates { get; set; }
    }

    public class Feature
    {
        [JsonProperty("id")]
        public string Id { get; set; }

        [JsonProperty("type")]
        public string Type { get; set; }

        [JsonProperty("properties")]
        public Properties Properties { get; set; }

        [JsonProperty("geometry")]
        public Geometry Geometry { get; set; }
    }

    public class Root
    {
        [JsonProperty("type")]
        public string Type { get; set; }

        [JsonProperty("parameters")]
        public Parameters Parameters { get; set; }

        [JsonProperty("bbox")]
        public List<double> Bbox { get; set; }

        [JsonProperty("features")]
        public List<Feature> Features { get; set; }
    }

}

我的控制器

public async Task<IActionResult> Weather()
{
     List<Root>  weatherlist = new  List<Root>();

     using (var httpClient = new HttpClient())
     {
         using (var response = await httpClient.GetAsync("http://labs.metoffice.gov.uk/edr/collections/obs_demo/radius?coords=POINT(-0.109421%2051.508558)&within=99&within-units=km&parameter-name=Dew%20point&datetime=2022-01-06T03:00Z/2022-01-06T05:00Z&crs=CRS84&f=GeoJSON"))
         {
                string apiResponse = await response.Content.ReadAsStringAsync();
                 weatherlist = JsonConvert.DeserializeObject<List<Root>>(apiResponse);
        }
    }

    return View(weatherlist);
}

这里是 API 输出的 json

{
 "type": "FeatureCollection",
 "parameters": {
 someThings there
 
  }
 },
 "bbox": [
  -0.123,
  0.123,
  0.123,
  0.123
 ],
 "features": [
  {
   "id": "EGWU",
   "type": "Feature",
   "properties": {
    "name": "tt",
    "Dew point": [
     -5
    ],
    "time": [
     "2022-01-06T04:50:00Z"
    ]
   },
   "geometry": {
    "type": "Point",
    "coordinates": [
     -0.417,
     51.55
    ]
   }
  },
  {
   "id": "EGMC",
   "type": "Feature",
   "properties": {
    "name": "SOUTHEND-ON-SEA",
    "Dew point": [
     -2
    ],
    "time": [
     "2022-01-06T04:50:00Z"
    ]
   },
   "geometry": {
    "type": "Point",
    "coordinates": [
     0.7,
     51.567
    ]
   }
  },
  {
   "id": "EGGW",
   "type": "Feature",
   "properties": {
    "name": "LUTON AIRPORT",
    "Dew point": [
     -3,
     -4
    ],
    "time": [
     "2022-01-06T04:50:00Z",
     "2022-01-06T04:20:00Z"
    ]
   },
   "geometry": {
    "type": "Point",
    "coordinates": [
     -0.367,
     51.867
    ]
   }
  },
  {
   "id": "EGSS",
   "type": "Feature",
   "properties": {
    "name": "STANSTED AIRPORT",
    "Dew point": [
     -4,
     -3
    ],
    "time": [
     "2022-01-06T04:50:00Z",
     "2022-01-06T04:20:00Z"
    ]
   },
   "geometry": {
    "type": "Point",
    "coordinates": [
     0.217,
     51.883
    ]
   }
  },
  {
   "id": "EGKK",
   "type": "Feature",
   "properties": {
    "name": "LONDON/GATWICK A",
    "Dew point": [
     -4,
     -5
    ],
    "time": [
     "2022-01-06T04:50:00Z",
     "2022-01-06T04:20:00Z"
    ]
   },
   "geometry": {
    "type": "Point",
    "coordinates": [
     -0.167,
     51.133
    ]
   }
  },
  {
   "id": "EGLF",
   "type": "Feature",
   "properties": {
    "name": "FARNBOROUGH",
    "Dew point": [
     -6,
     -6
    ],
    "time": [
     "2022-01-06T04:50:00Z",
     "2022-01-06T04:20:00Z"
    ]
   },
   "geometry": {
    "type": "Point",
    "coordinates": [
     -0.767,
     51.283
    ]
   }
  }
 ]
}

更新：这是我的看法

@Model IEnumerable<weather>

<table class="table table-sm table-striped table-bordered m-2">
    <thead>
        <tr>
            <th>type</th>
          
             <th>Bbox</th>
             
        </tr>
    </thead>
    <tbody>
        @foreach (var r in Model)
        {
            <tr>
                <td>@r.type</td>            
               <td>@r.Bbox</td>                            
            </tr>
        }
</tbody>
    
</table>

Answer 1

试试这个，你的 json 根是一个对象，而不是数组所以你必须使用 Root 而不是 List

 Root featureCollection=null;

string apiResponse = await response.Content.ReadAsStringAsync();
featureCollection = JsonConvert.DeserializeObject<Root>(apiResponse);

List<Feature> features=featureCollection.Feautures;

return View(features);

查看

@model List<Feature>

<table class="table table-sm table-striped table-bordered m-2">
    <thead>
        <tr>
            <th>Feature</th>
             <th>Property Name</th>
              <th>Property DewPoint</th>
              </tr>
    </thead>
    <tbody>
    @foreach (var feature in Model)
    {
        @foreach (var property in feature.Properties)
        {
            <tr>
                <td>@feature.Id</td>            
               <td>@property.Name</td> 
               <td>@property.DewPoint[0] : @property.DewPoint[1] </td>                               
            </tr>
        }
    }

</tbody>
    
</table>

使用 C# - ASP.NET Core MVC 反序列化 API Json 时出错

Error in Deserializing the API Json using C# - ASP.NET Core MVC

c#

json

geojson

.net-core

asp.net-core