ApiConn.cs

using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;
using System.Net;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;


namespace CurrencyExchange
{
    class ApiConn
    {
        private string all_curr_url = "https://free.currconv.com/api/v7/currencies?apiKey=a0cc285385352baf9649";
        IDictionary<string, string> numberNames = new Dictionary<string, string>(); 
        //<id,currencySymbol
        public ApiConn()
        {
            Debug.WriteLine("Api conn created");
            getAllCurrency();
            getCurrencyRate("USD", "PHP");
        }

        public JToken getAllCurrency()
        {
            string json_str = new WebClient().DownloadString(all_curr_url);
            Debug.WriteLine(json_str);
            JObject o = JObject.Parse(json_str);
            
            Debug.WriteLine(o["results"]["ALL"]);
            JToken res_o = o["results"];

            string coba = "IDR - I Dont know";
            Debug.WriteLine(coba.Substring(0,3));
            Debug.WriteLine(res_o[coba.Substring(0, 3)]);
            return res_o;
        }

        public Double getCurrencyRate(string from_, string to_)
        {
            string url_api = "https://free.currconv.com/api/v7/convert?q=" + from_ + "_" + to_ +
                "&compact=ultra&apiKey=a0cc285385352baf9649";
            string json_str = new WebClient().DownloadString(url_api);
            var id_convert = from_ + "_" + to_;
            JToken j_o = JToken.Parse(json_str);
            Debug.WriteLine(j_o[id_convert]);
            
            return j_o[id_convert].ToObject<double>();
        }
    }
}