c# HttpClient + GET + json body

httpclient_sample.cs

using System;
using System.IO;
using System.Net;
using System.Net.Http;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Text;
using System.Threading.Tasks;

namespace httpclient
{
    [DataContract]
    internal class SimpleReq
    {
        [DataMember]
        public string foo;
    }

    class Program
    {
        private static readonly HttpClient client = new HttpClient();

        public static byte[] ToJsonBinary<T>(T data)
        {
            var stream1 = new MemoryStream();
            var ser = new DataContractJsonSerializer(typeof(T));
            ser.WriteObject(stream1, data);

            stream1.Position = 0;
            StreamReader sr = new StreamReader(stream1);
            var jsonBody = sr.ReadToEnd();

            byte[] byteArray = Encoding.UTF8.GetBytes(jsonBody);
            return byteArray;
        }

        public static string ToJsonString<T>(T data)
        {
            var stream1 = new MemoryStream();
            var ser = new DataContractJsonSerializer(typeof(T));
            ser.WriteObject(stream1, data);

            stream1.Position = 0;
            StreamReader sr = new StreamReader(stream1);
            var jsonBody = sr.ReadToEnd();

            return jsonBody;
        }

        async Task<bool> RequestResource()
        {
            var host = "http://127.0.0.1:3100";
            var path = "/v1/user/mydata";
            var body = ToJsonString(new SimpleReq()
            {
                foo = "bar",
            });

            var request = new HttpRequestMessage(HttpMethod.Get, $"{host}{path}")
            {
                Headers = {
                    { HttpRequestHeader.ContentType.ToString(), "application/json"},
                },
                Content = new StringContent(body, Encoding.UTF8, "application/json"),
            };
            Console.WriteLine(request.Headers);
            var resp = await client.SendAsync(request);
            

            Console.WriteLine(resp.StatusCode);
            Console.WriteLine(await resp.Content.ReadAsStringAsync());
            return true;
        }

        static void Main(string[] args)
        {
            var x = new Program();
            var task = x.RequestResource();
            task.Wait();

            Console.WriteLine("Hello World!");
        }
    }
}