I don't want to distract you from what you doing but here is a stack thread that doing something like your work
How do I make calls to a REST api using c#?
and as you can see if your rest api only accepts json you should set that
using System;
using System.Collections.Generic;
using System.Net.Http;
using System.Net.Http.Headers;
namespace ConsoleProgram
{
public class DataObject
{
public string Name { get; set; }
}
public class Class1
{
private const string URL = "https://sub.domain.com/objects.json";
private string urlParameters = "?api_key=123";
static void Main(string[] args)
{
HttpClient client = new HttpClient();
client.BaseAddress = new Uri(URL);
// Add an Accept header for JSON format.
client.DefaultRequestHeaders.Accept.Add(
new MediaTypeWithQualityHeaderValue("application/json"));
// List data response.
HttpResponseMessage response = client.GetAsync(urlParameters).Result; // Blocking call!
if (response.IsSuccessStatusCode)
{
// Parse the response body. Blocking!
var dataObjects = response.Content.ReadAsAsync<IEnumerable<DataObject>>().Result;
foreach (var d in dataObjects)
{
Console.WriteLine("{0}", d.Name);
}
}
else
{
Console.WriteLine("{0} ({1})", (int)response.StatusCode, response.ReasonPhrase);
}
}
}
}