How to get JSON result into List

Question

I have my own code here and already get the JSON result then I haven't idea to move the JSON result into the interface (IEntities function) list below.

class GetCategory : IEntities
{
    private JsonHandle _jsonhandle;
    private string _ocategory;

    public async void TaskCategory()
    {
        _jsonhandle = new JsonHandle();
        _jsonhandle.StrAPI = "http://api.nytimes.com/svc/books/v3/lists/names.json?api-key=7bb034b7693d6f9753b2f68e00b98c78%3A16%3A73599437";
        var client = new HttpClient();
        Task<string> datatask = client.GetStringAsync(_jsonhandle.StrAPI);
        try
        {
            var JsonRead = await datatask;
            JObject oCategory = JObject.Parse(JsonRead);
            List<JToken> results = oCategory["results"].Children().ToList();

            //serialize JSON results into .NET objects
            List<object> dtCategory = new List<object>();
            foreach (JToken result in results)
            {
                object _dtcategory = JsonConvert.DeserializeObject<object>(result.ToString());
                dtCategory.Add(_dtcategory);
                var listname = result["list_name"];
            }
        }
        catch (Exception error)
        {
            Console.WriteLine("AW!" + error.StackTrace);
        }

    public List<object> BookCategory()
    {

    }
}

In the last function that in IEntities interface, I need to put my JSON result in interface List<object>.

Answer 1

When working with JSON, the first thing to do is creating a model object. In order to this, either you should analyze JSON output manually, or you can generate the model automatically by going to the following link and pasting either the JSON your are going to use or the service link;

json2csharp.com

I've just used your API link and the output generated is;

public class Result
{
    public string list_name { get; set; }
    public string display_name { get; set; }
    public string list_name_encoded { get; set; }
    public string oldest_published_date { get; set; }
    public string newest_published_date { get; set; }
    public string updated { get; set; }
}

public class RootObject
{
    public string status { get; set; }
    public string copyright { get; set; }
    public int num_results { get; set; }
    public List<Result> results { get; set; }
}

This will be our model.

Secondly, as far as I can see, what you want to do is only to get the result list, thus, as you deserialize the JSON output, you are going to use the Model.Result and move them into a list.

Then, to get the response, a private method can be used which that returns an async Task<string>, and on the BookCategory() method, you can get the Results and deserialize JSON and initialize a list based on your JSON object model;

public List<Model.Result> BookCategory()
{
    List<Model.Result> list = new List<Model.Result>();

    var model = JsonConvert.DeserializeObject<Model.RootObject>(TaskCategory().Result);

    list = model.results;

    return list;
}

Deserializing JSON is as simply as below;

var model = JsonConvert.DeserializeObject<Model.RootObject>(TaskCategory().Result);

Model.cs

using System.Collections.Generic;

namespace SO1
{
    public class Model
    {
        public class Result
        {
            public string list_name { get; set; }
            public string display_name { get; set; }
            public string list_name_encoded { get; set; }
            public string oldest_published_date { get; set; }
            public string newest_published_date { get; set; }
            public string updated { get; set; }
        }

        public class RootObject
        {
            public string status { get; set; }
            public string copyright { get; set; }
            public int num_results { get; set; }
            public List<Result> results { get; set; }
        }
    }
}

GetCategory.cs

using Newtonsoft.Json;
using System.Collections.Generic;
using System.Threading.Tasks;
using System.Net.Http;
using System;

namespace SO1
{
    public class GetCategory : IEntities
    {
        private String BaseUri;

        public GetCategory(string BaseUri)
        {
            this.BaseUri = BaseUri;
        }

        private async Task<string> TaskCategory()
        {
            var httpClient = new HttpClient();

            var parameters = new Dictionary<string, string>();
            parameters["text"] = "text";

            var response = await httpClient.GetStringAsync(BaseUri);

            return response;        
        }

        public List<Model.Result> BookCategory()
        {
            List<Model.Result> list = new List<Model.Result>();

            var model = JsonConvert.DeserializeObject<Model.RootObject>(TaskCategory().Result);

            list = model.results;

            return list;
        }

    }
}

IEntities

using System.Collections.Generic;

namespace SO1
{
    public interface IEntities
    {
        List<Model.Result> BookCategory();
    }
}

Program.cs

using System;
using System.Collections.Generic;

namespace SO1
{
    class Program
    {
        static void Main(string[] args)
        {
            string BaseUri = "http://api.nytimes.com/svc/books/v3/lists/names.json?api-key=7bb034b7693d6f9753b2f68e00b98c78%3A16%3A73599437";

            IEntities entity = new GetCategory(BaseUri);

            List<Model.Result> listBookCategory = new List<Model.Result>();

            listBookCategory = entity.BookCategory();

            foreach (Model.Result r in listBookCategory)
            {
                Console.WriteLine();
                Console.WriteLine("...List Name             : " + r.list_name);
                Console.WriteLine("...Display Name          : " + r.display_name);
                Console.WriteLine("...List Name Encoded     : " + r.list_name_encoded);
                Console.WriteLine("...Oldest Published Date : " + r.oldest_published_date);
                Console.WriteLine("...Oldest Published Date : " + r.newest_published_date);
                Console.WriteLine("...Updated               : " + r.updated);
                Console.WriteLine();
            }
        }
    }
}

Output (only first three results printed)

...List Name             : Combined Print and E-Book Fiction
...Display Name          : Combined Print & E-Book Fiction
...List Name Encoded     : combined-print-and-e-book-fiction
...Oldest Published Date : 2011-02-13
...Oldest Published Date : 2015-12-27
...Updated               : WEEKLY


...List Name             : Combined Print and E-Book Nonfiction
...Display Name          : Combined Print & E-Book Nonfiction
...List Name Encoded     : combined-print-and-e-book-nonfiction
...Oldest Published Date : 2011-02-13
...Oldest Published Date : 2015-12-27
...Updated               : WEEKLY


...List Name             : Hardcover Fiction
...Display Name          : Hardcover Fiction
...List Name Encoded     : hardcover-fiction
...Oldest Published Date : 2008-06-08
...Oldest Published Date : 2015-12-27
...Updated               : WEEKLY