Deserialize a JSON array into C#

Question

I am trying to query the Reddit API and looping over answers for a thread to get the answer I want. However, when I query the api (https://www.reddit.com/comments/2pfyg8.json?sort=top as an example) I'll get an json array with two objects. I want to loop over object number 2 because this is the object that has all the actual comments and the first object is the thread itself.

This seems like a challange in C#, or is atleast a challange for me. I use JSON.NET or Newtonsoft.Json to accomplish this and this is what I have so far:

var commentPath = $"http://www.reddit.com/comments/{questionId}.json?sort=top";
HttpResponseMessage commentResponse = await client.GetAsync(commentPath);
var commentJson = await response.Content.ReadAsStringAsync();
var answers = JsonConvert.DeserializeObject<dynamic>(commentJson);

int commentCount = 0;
foreach (var answerContainer in answers[1].data.children) { }

I have also tried to use http://json2csharp.com/ to generate the correct type for me to use instead of dynamic but it seems to be incorrect as well.

This is the error I recieve:

 System.ArgumentException: Accessed JObject values with invalid key value: 1. Object property name expected. vid Newtonsoft.Json.Linq.JObject.get_Item(Object key) vid CallSite.Target(Closure , CallSite , Object , Int32 )

I would be very glad if someone were able to help me in my quest to get the comment I am looking for.

Have you tried using the Paste JSON as classes feature in Visual Studio? blogs.msdn.microsoft.com/webdev/2012/12/18/… — Ben Cottrell
– Ben Cottrell, Commented Jan 29, 2017 at 11:32
@BenCottrell No, but when I am trying that, it identifies my content as xml and gives an error. :/ — Ms01
– Ms01, Commented Jan 29, 2017 at 11:37

Victor Leontyev · Accepted Answer · 2017-01-29 11:38:00Z

1

Based on JSON response from Reddit, I generated this classes (Paste JSON as Classes function in Visual Studio):

public class reddit
{
    public string kind { get; set; }
    public Data data { get; set; }
}

public class Data
{
    public string modhash { get; set; }
    public Child[] children { get; set; }
    public object after { get; set; }
    public object before { get; set; }
}

public class Child
{
    public string kind { get; set; }
    public Data1 data { get; set; }
}

public class Data1
{
    public bool contest_mode { get; set; }
    public object banned_by { get; set; }
    public Media_Embed media_embed { get; set; }
    public string subreddit { get; set; }
    public string selftext_html { get; set; }
    public string selftext { get; set; }
    public object likes { get; set; }
    public object suggested_sort { get; set; }
    public object[] user_reports { get; set; }
    public object secure_media { get; set; }
    public bool saved { get; set; }
    public string id { get; set; }
    public int gilded { get; set; }
    public Secure_Media_Embed secure_media_embed { get; set; }
    public bool clicked { get; set; }
    public object report_reasons { get; set; }
    public string author { get; set; }
    public object media { get; set; }
    public int score { get; set; }
    public object approved_by { get; set; }
    public bool over_18 { get; set; }
    public string domain { get; set; }
    public bool hidden { get; set; }
    public int num_comments { get; set; }
    public string thumbnail { get; set; }
    public string subreddit_id { get; set; }
    public bool edited { get; set; }
    public object link_flair_css_class { get; set; }
    public object author_flair_css_class { get; set; }
    public int downs { get; set; }
    public bool archived { get; set; }
    public object removal_reason { get; set; }
    public bool stickied { get; set; }
    public bool is_self { get; set; }
    public bool hide_score { get; set; }
    public bool spoiler { get; set; }
    public string permalink { get; set; }
    public bool locked { get; set; }
    public string name { get; set; }
    public float created { get; set; }
    public string url { get; set; }
    public object author_flair_text { get; set; }
    public bool quarantine { get; set; }
    public string title { get; set; }
    public float created_utc { get; set; }
    public object link_flair_text { get; set; }
    public int ups { get; set; }
    public float upvote_ratio { get; set; }
    public object[] mod_reports { get; set; }
    public bool visited { get; set; }
    public object num_reports { get; set; }
    public object distinguished { get; set; }
    public string link_id { get; set; }
    public object replies { get; set; }
    public string parent_id { get; set; }
    public int controversiality { get; set; }
    public string body { get; set; }
    public string body_html { get; set; }
    public bool score_hidden { get; set; }
}

public class Media_Embed
{
}

public class Secure_Media_Embed
{
}

And then, working code looks like that:

using (var client = new HttpClient())
        {
            var commentPath = $"http://www.reddit.com/comments/{questionId}.json?sort=top";
            HttpResponseMessage commentResponse = client.GetAsync(commentPath).Result;
            var commentJson = commentResponse.Content.ReadAsStringAsync().Result;
            var answers = JsonConvert.DeserializeObject<reddit[]>(commentJson);

            int commentCount = 0;
            foreach (var answerContainer in answers[1].data.children)
            {
            }
        }

answered Jan 29, 2017 at 11:38

Victor Leontyev

8,7442 gold badges19 silver badges37 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Ms01 Over a year ago

This is exactly what I did before but then I get this error:

Newtonsoft.Json.JsonSerializationException: Cannot deserialize the current JSON object (e.g. {“name”:”value”}) into type ‘Sofie.Models.Reddit[]’ because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly. To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List<T>) that can be deserialized from a JSON object.

But the json is an array!

Victor Leontyev Over a year ago

I checked my solution with this url: reddit.com/comments/2pfyg8.json?sort=top and everything is working fine without any errors

Ms01 Over a year ago

If I use just the type and not an array it works but the children seems to be the thread and not the actual comments.

Ms01 Over a year ago

Just realized a huge mistake, var commentJson = await response.Content.ReadAsStringAsync(); should be var commentJson = await commentResponse.Content.ReadAsStringAsync(); since I am doing another request before this one in order to find the thread. With that change, it of course works just fine.

Collectives™ on Stack Overflow

Deserialize a JSON array into C#

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related