61

我有以下从 Twitter 获得的 Json

     +      token   {[
  {
    "trends": [
      {
        "name": "Croke Park II",
        "url": "http://twitter.com/search?q=%22Croke+Park+II%22",
        "promoted_content": null,
        "query": "%22Croke+Park+II%22",
        "events": null
      },
      {
        "name": "#twiznight",
        "url": "http://twitter.com/search?q=%23twiznight",
        "promoted_content": null,
        "query": "%23twiznight",
        "events": null
      },
      {
        "name": "#Phanhattan",
        "url": "http://twitter.com/search?q=%23Phanhattan",
        "promoted_content": null,
        "query": "%23Phanhattan",
        "events": null
      },
      {
        "name": "#VinB",
        "url": "http://twitter.com/search?q=%23VinB",
        "promoted_content": null,
        "query": "%23VinB",
        "events": null
      },
      {
        "name": "#Boston",
        "url": "http://twitter.com/search?q=%23Boston",
        "promoted_content": null,
        "query": "%23Boston",
        "events": null
      },
      {
        "name": "#rtept",
        "url": "http://twitter.com/search?q=%23rtept",
        "promoted_content": null,
        "query": "%23rtept",
        "events": null
      },
      {
        "name": "Facebook",
        "url": "http://twitter.com/search?q=Facebook",
        "promoted_content": null,
        "query": "Facebook",
        "events": null
      },
      {
        "name": "Ireland",
        "url": "http://twitter.com/search?q=Ireland",
        "promoted_content": null,
        "query": "Ireland",
        "events": null
      },
      {
        "name": "Everton",
        "url": "http://twitter.com/search?q=Everton",
        "promoted_content": null,
        "query": "Everton",
        "events": null
      },
      {
        "name": "Twitter",
        "url": "http://twitter.com/search?q=Twitter",
        "promoted_content": null,
        "query": "Twitter",
        "events": null
      }
    ],
    "as_of": "2013-04-17T13:05:30Z",
    "created_at": "2013-04-17T12:51:41Z",
    "locations": [
      {
        "name": "Dublin",
        "woeid": 560743
      }
    ]
  }
]}  Newtonsoft.Json.Linq.JToken {Newtonsoft.Json.Linq.JArray}

问题是我似乎无法访问任何元素。我已经尝试过 foreach 循环和正常的 for 循环，但似乎永远无法访问单个元素，它总是最终访问整个区域。

知道如何访问这个 Json JArray 中的各个元素吗？

4

4 回答 4

73

有一个更简单的解决方案。
只需将 as 的项目JArray视为JObject。

假设我们有这样的 JSON 对象数组：

JArray jArray = JArray.Parse(@"[
              {
                ""name"": ""Croke Park II"",
                ""url"": ""http://twitter.com/search?q=%22Croke+Park+II%22"",
                ""promoted_content"": null,
                ""query"": ""%22Croke+Park+II%22"",
                ""events"": null
              },
              {
                ""name"": ""Siptu"",
                ""url"": ""http://twitter.com/search?q=Siptu"",
                ""promoted_content"": null,
                ""query"": ""Siptu"",
                ""events"": null
              }]");

要访问每个项目，只需执行以下操作：

foreach (JObject item in jArray) // <-- Note that here we used JObject instead of usual JProperty
{
    string name = item.GetValue("name").ToString();
    string url = item.GetValue("url").ToString();
    // ...
}
于 2017-01-23T16:19:16.643 回答
61

更新 - 我验证了以下作品。也许您的 JArray 的创建不太正确。

[TestMethod]
    public void TestJson()
    {
        var jsonString = @"{""trends"": [
              {
                ""name"": ""Croke Park II"",
                ""url"": ""http://twitter.com/search?q=%22Croke+Park+II%22"",
                ""promoted_content"": null,
                ""query"": ""%22Croke+Park+II%22"",
                ""events"": null
              },
              {
                ""name"": ""Siptu"",
                ""url"": ""http://twitter.com/search?q=Siptu"",
                ""promoted_content"": null,
                ""query"": ""Siptu"",
                ""events"": null
              },
              {
                ""name"": ""#HNCJ"",
                ""url"": ""http://twitter.com/search?q=%23HNCJ"",
                ""promoted_content"": null,
                ""query"": ""%23HNCJ"",
                ""events"": null
              },
              {
                ""name"": ""Boston"",
                ""url"": ""http://twitter.com/search?q=Boston"",
                ""promoted_content"": null,
                ""query"": ""Boston"",
                ""events"": null
              },
              {
                ""name"": ""#prayforboston"",
                ""url"": ""http://twitter.com/search?q=%23prayforboston"",
                ""promoted_content"": null,
                ""query"": ""%23prayforboston"",
                ""events"": null
              },
              {
                ""name"": ""#TheMrsCarterShow"",
                ""url"": ""http://twitter.com/search?q=%23TheMrsCarterShow"",
                ""promoted_content"": null,
                ""query"": ""%23TheMrsCarterShow"",
                ""events"": null
              },
              {
                ""name"": ""#Raw"",
                ""url"": ""http://twitter.com/search?q=%23Raw"",
                ""promoted_content"": null,
                ""query"": ""%23Raw"",
                ""events"": null
              },
              {
                ""name"": ""Iran"",
                ""url"": ""http://twitter.com/search?q=Iran"",
                ""promoted_content"": null,
                ""query"": ""Iran"",
                ""events"": null
              },
              {
                ""name"": ""#gaa"",
                ""url"": ""http://twitter.com/search?q=%23gaa"",
                ""promoted_content"": null,
                ""query"": ""gaa"",
                ""events"": null
              },
              {
                ""name"": ""Facebook"",
                ""url"": ""http://twitter.com/search?q=Facebook"",
                ""promoted_content"": null,
                ""query"": ""Facebook"",
                ""events"": null
              }]}";

        var twitterObject = JToken.Parse(jsonString);
        var trendsArray = twitterObject.Children<JProperty>().FirstOrDefault(x => x.Name == "trends").Value;


        foreach (var item in trendsArray.Children())
        {
            var itemProperties = item.Children<JProperty>();
            //you could do a foreach or a linq here depending on what you need to do exactly with the value
            var myElement = itemProperties.FirstOrDefault(x => x.Name == "url");
            var myElementValue = myElement.Value; ////This is a JValue type
        }
    }

因此，在您的 JArray 上调用 Children 以获取 JArray 中的每个 JObject。在每个 JObject 上调用 Children 以访问对象属性。

foreach(var item in yourJArray.Children())
{
    var itemProperties = item.Children<JProperty>();
    //you could do a foreach or a linq here depending on what you need to do exactly with the value
    var myElement = itemProperties.FirstOrDefault(x => x.Name == "url");
    var myElementValue = myElement.Value; ////This is a JValue type
}
于 2013-04-16T19:48:39.317 回答
9

一旦有了 JArray，您就可以像对待任何其他 Enumerable 对象一样对待它，并且使用 linq 您可以访问它们、检查它们、验证它们并选择它们。

var str = @"[1, 2, 3]";
var jArray = JArray.Parse(str);
Console.WriteLine(String.Join("-", jArray.Where(i => (int)i > 1).Select(i => i.ToString())));
于 2015-07-30T02:44:43.833 回答
1 
void ConvertToJArray(object headers)
{
    //where headers is your Twitter response
    JObject JObj = (JObject)headers;//Parse to JObject
    JArray JArr = (JArray)JObj["trends"];//Get the trends array as JArray
    for (int i = 0; i < JArr.Count; i++)
    {
        var Name = JArr[i]["name"].ToString();
        var URL = JArr[i]["url"].ToString();
    }
}
于 2021-07-08T12:05:49.490 回答