我试图在C＃中解析一些JSON并且出现错误。
＆＃34; text＆＃34;下面的变量是有效的JSON，它具有＆＃34;每日＆＃34;字段，其中包含＆＃34;数据＆＃34; field，有一个数组值，第一个元素是我需要的对象。
我试图这样做：
dynamic blobtext = JObject.Parse(text); //line 61
JObject weather = blobtext.daily.data[0]; //line 62
这引发了以下错误：
System.ArgumentNullException: Value cannot be null.
Parameter name: value
at Newtonsoft.Json.Linq.JToken.EnsureValue(JToken value)
at Newtonsoft.Json.Linq.JToken.op_Explicit(JToken value)
at DbMgr.DarkSky.<UpdateWeatherHistory>d__2.MoveNext() in C:\...\Program.cs:line 62
现在，我知道那条路上有一个有效的对象。有什么想法会发生什么？
编辑：JSON低于
{
"latitude": 31.2291308312072,
"longitude": 34.3353435935438,
"timezone": "Africa/Cairo",
"offset": 2,
"currently": {
"time": 1262390401,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 11.1,
"apparentTemperature": 11.1,
"dewPoint": 7.39,
"humidity": 0.78,
"windSpeed": 1.19,
"windBearing": 141,
"visibility": 8.66,
"cloudCover": 0.1,
"pressure": 1018.57,
"uvIndex": 0
},
"hourly": {
"summary": "Clear throughout the day.",
"icon": "clear-day",
"data": [{
"time": 1262383200,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 10.82,
"apparentTemperature": 10.82,
"dewPoint": 8.31,
"humidity": 0.84,
"windSpeed": 1.99,
"windBearing": 148,
"visibility": 8.9,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262386800,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 10.54,
"apparentTemperature": 10.54,
"dewPoint": 8.49,
"humidity": 0.87,
"windSpeed": 2.09,
"windBearing": 169,
"visibility": 8.24,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262390400,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 11.1,
"apparentTemperature": 11.1,
"dewPoint": 7.39,
"humidity": 0.78,
"windSpeed": 1.19,
"windBearing": 141,
"visibility": 8.66,
"cloudCover": 0.1,
"pressure": 1018.57,
"uvIndex": 0
},
{
"time": 1262394000,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 10.06,
"apparentTemperature": 10.06,
"dewPoint": 7.29,
"humidity": 0.83,
"windSpeed": 1.81,
"windBearing": 157,
"visibility": 8.14,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262397600,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 10.37,
"apparentTemperature": 10.37,
"dewPoint": 7.24,
"humidity": 0.81,
"windSpeed": 2.07,
"windBearing": 158,
"visibility": 8.27,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262401200,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 10.07,
"apparentTemperature": 10.07,
"dewPoint": 7.31,
"humidity": 0.83,
"windSpeed": 1.34,
"windBearing": 134,
"visibility": 9,
"cloudCover": 0,
"pressure": 1018.52,
"uvIndex": 0
},
{
"time": 1262404800,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 10.01,
"apparentTemperature": 10.01,
"dewPoint": 6.43,
"humidity": 0.78,
"windSpeed": 3.46,
"windBearing": 166,
"visibility": 8.27,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262408400,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 10.92,
"apparentTemperature": 10.92,
"dewPoint": 6.67,
"humidity": 0.75,
"windSpeed": 1.52,
"windBearing": 157,
"visibility": 8.56,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262412000,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 11.97,
"apparentTemperature": 11.97,
"dewPoint": 6.78,
"humidity": 0.71,
"windSpeed": 1.15,
"windBearing": 151,
"visibility": 10.77,
"cloudCover": 0.11,
"pressure": 1018.68,
"uvIndex": 1
},
{
"time": 1262415600,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 16.46,
"apparentTemperature": 16.46,
"dewPoint": 7.92,
"humidity": 0.57,
"windSpeed": 3.02,
"windBearing": 177,
"visibility": 9.38,
"cloudCover": 0,
"uvIndex": 1
},
{
"time": 1262419200,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 19.13,
"apparentTemperature": 19.13,
"dewPoint": 7.51,
"humidity": 0.47,
"windSpeed": 4.64,
"windBearing": 162,
"visibility": 9.48,
"cloudCover": 0,
"uvIndex": 2
},
{
"time": 1262422800,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 22.06,
"apparentTemperature": 22.06,
"dewPoint": 6.72,
"humidity": 0.37,
"windSpeed": 2.53,
"windBearing": 181,
"visibility": 10.77,
"cloudCover": 0.21,
"pressure": 1017.43,
"uvIndex": 3
},
{
"time": 1262426400,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 23.49,
"apparentTemperature": 23.49,
"dewPoint": 5.71,
"humidity": 0.32,
"windSpeed": 3.69,
"windBearing": 195,
"visibility": 9.75,
"cloudCover": 0,
"uvIndex": 3
},
{
"time": 1262430000,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 24.63,
"apparentTemperature": 24.63,
"dewPoint": 7.13,
"humidity": 0.33,
"windSpeed": 4.13,
"windBearing": 195,
"visibility": 9.75,
"cloudCover": 0,
"uvIndex": 3
},
{
"time": 1262433600,
"summary": "Partly Cloudy",
"icon": "partly-cloudy-day",
"precipType": "rain",
"temperature": 25.28,
"apparentTemperature": 25.28,
"dewPoint": 4.48,
"humidity": 0.26,
"windSpeed": 3.21,
"windBearing": 200,
"visibility": 10.88,
"cloudCover": 0.34,
"pressure": 1014.82,
"uvIndex": 1
},
{
"time": 1262437200,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 24.79,
"apparentTemperature": 24.79,
"dewPoint": 4.9,
"humidity": 0.28,
"windSpeed": 2.95,
"windBearing": 218,
"visibility": 9.4,
"cloudCover": 0,
"uvIndex": 1
},
{
"time": 1262440800,
"summary": "Clear",
"icon": "clear-day",
"precipType": "rain",
"temperature": 23.73,
"apparentTemperature": 23.73,
"dewPoint": 5.56,
"humidity": 0.31,
"windSpeed": 1.65,
"windBearing": 235,
"visibility": 9.4,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262444400,
"summary": "Partly Cloudy",
"icon": "partly-cloudy-night",
"precipType": "rain",
"temperature": 21.36,
"apparentTemperature": 21.36,
"dewPoint": 5.29,
"humidity": 0.35,
"windSpeed": 1.38,
"windBearing": 216,
"visibility": 10.91,
"cloudCover": 0.38,
"pressure": 1014.74,
"uvIndex": 0
},
{
"time": 1262448000,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 18.11,
"apparentTemperature": 18.11,
"dewPoint": 6.43,
"humidity": 0.46,
"windSpeed": 1.01,
"windBearing": 171,
"visibility": 9.59,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262451600,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 17.63,
"apparentTemperature": 17.63,
"dewPoint": 6.84,
"humidity": 0.49,
"windSpeed": 0.93,
"windBearing": 147,
"visibility": 9.59,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262455200,
"summary": "Partly Cloudy",
"icon": "partly-cloudy-night",
"precipType": "rain",
"temperature": 15.95,
"apparentTemperature": 15.95,
"dewPoint": 6.43,
"humidity": 0.53,
"windSpeed": 0.9,
"windBearing": 174,
"visibility": 10.12,
"cloudCover": 0.38,
"pressure": 1015.66,
"uvIndex": 0
},
{
"time": 1262458800,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 14.79,
"apparentTemperature": 14.79,
"dewPoint": 6.27,
"humidity": 0.57,
"windSpeed": 1.69,
"windBearing": 164,
"visibility": 9.48,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262462400,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 14.67,
"apparentTemperature": 14.67,
"dewPoint": 6.08,
"humidity": 0.56,
"windSpeed": 1.54,
"windBearing": 311,
"visibility": 9.48,
"cloudCover": 0,
"uvIndex": 0
},
{
"time": 1262466000,
"summary": "Clear",
"icon": "clear-night",
"precipType": "rain",
"temperature": 13.12,
"apparentTemperature": 13.12,
"dewPoint": 4.67,
"humidity": 0.57,
"windSpeed": 0.83,
"windBearing": 184,
"visibility": 10.28,
"cloudCover": 0.19,
"pressure": 1016.1,
"uvIndex": 0
}]
},
"daily": {
"data": [{
"time": 1262383200,
"summary": "Clear throughout the day.",
"icon": "clear-day",
"sunriseTime": 1262407368,
"sunsetTime": 1262443961,
"moonPhase": 0.56,
"precipType": "rain",
"temperatureMin": 10.01,
"temperatureMinTime": 1262404800,
"temperatureMax": 25.28,
"temperatureMaxTime": 1262433600,
"apparentTemperatureMin": 10.01,
"apparentTemperatureMinTime": 1262404800,
"apparentTemperatureMax": 25.28,
"apparentTemperatureMaxTime": 1262433600,
"dewPoint": 6.58,
"humidity": 0.57,
"windSpeed": 1.83,
"windBearing": 179,
"visibility": 9.46,
"cloudCover": 0.07,
"pressure": 1016.81,
"uvIndex": 3,
"uvIndexTime": 1262422800
}]
},
"flags": {
"sources": ["isd"],
"isd-stations": ["401762-99999",
"401790-99999",
"401800-99999",
"401830-99999",
"401900-99999",
"401980-99999",
"402400-99999",
"402700-99999",
"402720-99999",
"402960-99999",
"403100-99999",
"623350-99999",
"623360-99999",
"623370-99999",
"624520-99999",
"624530-99999"],
"units": "si"
}
}
答案 0 :(得分：1)
使用var weather = blobtext.daily.data[0];代替JObject weather = blobtext.daily.data[0];
实际上blobtext.daily.data[0];不返回JObject，而是返回一些未知类型。所以你不能将它分配给JObject。
如果你问为什么没有编译时错误，我可以说是因为动态变量。 ：）