C# 如何访问 JArray 的元素
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How to access elements of a JArray
提问by Stephen Hynes
I have the following Json gotten from Twitter
我从 Twitter 获得了以下 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}
Problem is I can't seem to access any of the elements. I have tried foreach loops and normal for loops and can never seem to access individual elemets it always ends up accessing the whole area.
问题是我似乎无法访问任何元素。我尝试过 foreach 循环和普通的 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。
Any idea how I access the individual elements in this Json JArray?
知道如何访问这个 Json JArray 中的各个元素吗？
采纳答案by cgotberg
Update - I verified the below works. Maybe the creation of your JArray isn't quite right.
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
}
}
So call Children on your JArray to get each JObject in JArray. Call Children on each JObject to access the objects properties.
因此，调用 JArray 上的 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
}
回答by Ghasan
Once you have a JArray you can treat it just like any other Enumerable object, and using linq you can access them, check them, verify them, and select them.
一旦你有了一个 JArray，你就可以像对待任何其他 Enumerable 对象一样对待它，并且使用 linq 你可以访问它们、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())));
回答by Just Shadow
Actually treating the items of JArrayas JObjectworks.
Here is an example:
Let's say we have such array of JSON objects:
实际上将项目JArray视为JObject作品。
这是一个例子：
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
}]");
To get access each item we just do the following:
要访问每个项目，我们只需执行以下操作：
foreach (JObject item in jArray)
{
string name = item.GetValue("name").ToString();
string url = item.GetValue("url").ToString();
// ...
}
