问题描述

我正在使用 Guardian API 来尝试检索故事，但一直收到异常.json 字符串包含以下 json，但是我无法使用 LINQ 访问正文.

I am using the guardian API to try and retrieve stories but keep receiving an exception. The string of json contains the below json, however I can't access the body using LINQ.

这里是:

{
    "response":{
    "status":"ok",
    "userTier":"approved",
    "total":1,
    "startIndex":1,
    "pageSize":10,
    "currentPage":1,
    "pages":1,
    "orderBy":"newest",
    "results":[{
      "id":"sustainable-business/sustainable-finance-where-next-open-thread",
      "sectionId":"sustainable-business",
      "sectionName":"Guardian Sustainable Business",
      "webPublicationDate":"2014-02-13T13:27:00Z",
      "webTitle":"Where next for sustainable finance? - open thread",
      "webUrl":"http://www.theguardian.com/sustainable-business/sustainable-finance-where-next-open-thread",
      "apiUrl":"http://content.guardianapis.com/sustainable-business/sustainable-finance-where-next-open-thread",
      "fields":{
        "body":"<img src="http://hits.theguardian.com/b/ss/guardiangu-api/1/H.20.3/98867?ns=guardian&amp;pageName=Where+next+for+sustainable+finance%3F+-+open+thread+Article+2043222&amp;ch=Guardian+Sustainable+Business&amp;c2=461773&amp;c4=MIC%3A+Finance+%28GSB%29%2CMIC%3A+Guardian+Sustainable+Business%2CPRO%3A+Sustainability+%28Guardian+Professional%29&amp;c3=theguardian.com&amp;c6=Laura+Paddison&amp;c7=14-Feb-13&amp;c8=2043222&amp;c9=Article" width="1" height="1" />..."
      }
     }]
     }
}

我已经尝试了所有方法，包括:

I have tried every thing including this:

string story = (string)ja["response"]["results"]["fields"]["body"];

更新:

public partial class Story : PhoneApplicationPage
{
    string url;
    string jsonData;

    // Http used so the json can be retrived via the get async methods
    HttpClient webClient = new HttpClient();

    protected override void OnNavigatedTo(NavigationEventArgs e)
    {
        if (NavigationContext.QueryString.ContainsKey("key"))
        {
            string encodedValue = NavigationContext.QueryString["key"];
            url = Uri.UnescapeDataString(encodedValue);
            textBox.Text = url;
            guardianPanorama();
        }
    }
    private async void guardianPanorama()
    {
        try
        {
            HttpResponseMessage Result = await webClient.GetAsync(url);

            // This takes the http response content and is turned into a string
            jsonData = await Result.Content.ReadAsStringAsync();
           
            JObject ja = JObject.Parse(jsonData);

            // This takes the current bitcoin price and formats it so there is the      correct amount of decimal places
            string story = (string)ja["response"]["results"]["fields"]["body"];

            // It then gets added to the textbox
            textBox.Text = story;
        }
        catch (Exception errors)
        {
            MessageBox.Show("There has been a error with the Guardian API");
            Console.WriteLine("An error occured:" + errors);
        }
    }
}

例外:

System.ArgumentException:使用无效键值访问的 JArray 值:字段".应为数组位置索引.

System.ArgumentException: Accessed JArray values with invalid key value: "fields". Array position index expected.

在 Newtonsoft.Json.Linq.JArray.get_Item(对象键)

at Newtonsoft.Json.Linq.JArray.get_Item(Object key)

推荐答案

如果替换

// This takes the current bitcoin price and formats it so there is the correct amount of decimal places
string story = (string)ja["response"]["results"]["fields"]["body"];

与

// This takes the current bitcoin price and formats it so there is the correct amount of decimal places
string story = (string)ja["response"]["results"][0]["fields"]["body"];

这应该适用于您的示例.请注意您提供的示例中结果后面的方括号，它表示应该在您的访问代码中考虑的数组.

that should work for your example. Note the square bracket after results in the example you provided, that indicates an array that should be accounted for in your access code.

这篇关于使用无效键值访问的 JArray 值:“字段".预期数组位置索引的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持跟版网！