using System;

using System.Collections;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Runtime.Serialization.Formatters;

using System.IO;

using System.Data;

using System.ComponentModel.DataAnnotations;

using System.Globalization;

using System.Reflection;

using System.Collections.ObjectModel;

using System.Threading.Tasks;

using System.Net.Http;

​

using System.Text.Json;

using System.Text.Json.Serialization;

​

using NUnit.Framework; // Throws NUnit.Framework.AssertionException

​

//https://stackoverflow.com/questions/66258830/how-to-deserialize-part-of-json-using-system-text-json-in-net-core-3-0

​

    public class MarsWheather {

        [JsonPropertyName("First_UTC")]

        public DateTime FirstUTC { get; set; }

        [JsonPropertyName("Last_UTC")]

        public DateTime LastUTC { get; set; }

        [JsonPropertyName("Season")]

        [JsonConverter(typeof(JsonStringEnumConverter))]

        public Season MarsSeason { get; set; }

        [JsonPropertyName("PRE")]

        public DataDescription AtmosphericPressure { get; set; }

    }

​

    public enum Season {

        winter,

        spring,

        summer,

        autumn

    }

​

    public class DataDescription{

        [JsonPropertyName("av")]

        public double Average { get; set; }

        [JsonPropertyName("ct")]

        public double TotalCount { get; set; }

        [JsonPropertyName("mn")]

        public double Minimum { get; set; }

        [JsonPropertyName("mx")]

        public double Maximum { get; set; }

    } 

​

​

    public class Program

    {

        private static async Task<Dictionary<string, MarsWheather>> GetMarsWheatherRootObject(string uri, HttpClient httpClient)

        {

            using var httpResponse = await httpClient.GetAsync(uri, HttpCompletionOption.ResponseHeadersRead);

​

            httpResponse.EnsureSuccessStatusCode(); // throws if not 200-299

​

            var stream = await httpResponse.Content.ReadAsStreamAsync();

            var root = await System.Text.Json.JsonSerializer.DeserializeAsync<Dictionary<string, MarsWheather>>(

                stream, 

                new System.Text.Json.JsonSerializerOptions 

                { 

                    PropertyNameCaseInsensitive = true 

                });

            return root;

        }

        public static async Task Test()

        {

            var client = new HttpClient();

            var url = @"https://api.nasa.gov/insight_weather/?api_key=DEMO_KEY&feedtype=json&ver=1.0";

            var items = await GetMarsWheatherRootObject(url, client);

            items.Dump();

            var newJson = JsonSerializer.Serialize(items, new JsonSerializerOptions { WriteIndented = true });

            Console.WriteLine("Deserialized and re-serialized {0}:", "MarsWheatherRootObject");

            Console.WriteLine(newJson);

        }

        public static async Task Main(string[] args)

        {

            Console.WriteLine("Environment version: {0} ({1})", System.Runtime.InteropServices.RuntimeInformation.FrameworkDescription , GetNetCoreVersion());

            Console.WriteLine("{0} version: {1}", typeof(JsonSerializer).Assembly.GetName().Name,  typeof(JsonSerializer).Assembly.FullName);

            Console.WriteLine();

​

            try

            {

                await Test();

            }

            catch (Exception ex)

            {

                Console.WriteLine("Failed with unhandled exception: ");

                Console.WriteLine(ex);

                throw;

            }

        }

        public static string GetNetCoreVersion()

        {

            //https://techblog.dorogin.com/how-to-detect-net-core-version-in-runtime-ecd65ad695be

            //

            var assembly = typeof(System.Runtime.GCSettings).GetTypeInfo().Assembly;

            var assemblyPath = assembly.Location.Split(new[] { '/', '\\' }, StringSplitOptions.RemoveEmptyEntries);

            int netCoreAppIndex = Array.IndexOf(assemblyPath, "Microsoft.NETCore.App");

            if (netCoreAppIndex > 0 && netCoreAppIndex < assemblyPath.Length - 2)

                return assemblyPath[netCoreAppIndex + 1];

            return null;

        }

    }

​