Question

我有jsonstring：

{
 "kind": "youtube#videoListResponse",
 "etag": "\"NO6QTeg0-3ShswIeqLchQ_mzWJs/o3L50v5R2WwnOWFaoCXQIOzRQt8\"",
 "pageInfo": {
  "totalResults": 1,
  "resultsPerPage": 1
 },
 "items": [
  {
   "kind": "youtube#video",
   "etag": "\"NO6QTeg0-3ShswIeqLchQ_mzWJs/emOU-eLbb23xAEX_1JcXPAXYJUY\"",
   "id": "7eCPp1WLpyA",
   "contentDetails": {
    "duration": "PT7M10S",
    "dimension": "2d",
    "definition": "hd",
    "caption": "false",
    "licensedContent": true
   },
   "statistics": {
    "viewCount": "1603",
    "likeCount": "454",
    "dislikeCount": "6",
    "favoriteCount": "0",
    "commentCount": "107"
   }
  }
 ]
}

我想获得持续时间的价值是＆＃34; PT7M10S＆＃34;

我编码：

 var obj = JObject.Parse(jsonString);
 var url = (string)obj["contentDetails"]["duration"];
 return url;

但我收到错误：对象引用未设置为对象的实例请帮忙！感谢。

Answer 1

您要查找的属性位于items数组中。所以你需要做以下事情：

var obj = JObject.Parse(json);
var url = obj["items"][0]["contentDetails"]["duration"];

小提琴： https://dotnetfiddle.net/iSNzAe

编辑：更好的方法是使用一个类（请参阅更新的小提琴）

public static void Main()
{       
    var json = 
    @"{
     ""kind"": ""youtube#videoListResponse"",
     ""etag"": ""\""NO6QTeg0-3ShswIeqLchQ_mzWJs/o3L50v5R2WwnOWFaoCXQIOzRQt8\"""",
     ""pageInfo"": {
      ""totalResults"": 1,
      ""resultsPerPage"": 1
     },
     ""items"": [
      {
       ""kind"": ""youtube#video"",
       ""etag"": ""\""NO6QTeg0-3ShswIeqLchQ_mzWJs/emOU-eLbb23xAEX_1JcXPAXYJUY\"""",
       ""id"": ""7eCPp1WLpyA"",
       ""contentDetails"": {
        ""duration"": ""PT7M10S"",
        ""dimension"": ""2d"",
        ""definition"": ""hd"",
        ""caption"": ""false"",
        ""licensedContent"": true
       },
       ""statistics"": {
        ""viewCount"": ""1603"",
        ""likeCount"": ""454"",
        ""dislikeCount"": ""6"",
        ""favoriteCount"": ""0"",
        ""commentCount"": ""107""
       }
      }
     ]
    }";

    var obj = JsonConvert.DeserializeObject<Response>(json);
    var duration = obj.items.First().contentDetails.duration;

    Console.WriteLine(duration);

}

public class Response
{
    public IEnumerable<ResponseItem> items;
}

public class ResponseItem 
{
    public ContentDetails contentDetails;
}

public class ContentDetails
{
    public string duration;
}

我怎么能从json得到一些价值而不是roor？

1 个答案: