c# Example for University API

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Web;
using System.Net;
using System.IO;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System.Collections;

namespace university_api
{
    public partial class Form1 : Form
    {
        ArrayList universities_id = new ArrayList();
        ArrayList faculties_id = new ArrayList();

        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            string responseFromServer = pigonUniApi("http://pigon.ws/university/list");
            List<Query> universities = (List<Query>)JsonConvert.DeserializeObject(responseFromServer,typeof(List<Query>)); 
            foreach (Query obj in universities)
            {
                comboBox1.Items.Add(obj.name);
                universities_id.Add(obj.id);
            }
        }

        public string pigonUniApi(string Url)
        {
            string requestUri = String.Format(Url);
            HttpWebRequest request = (HttpWebRequest)WebRequest.Create(requestUri);
            Stream dataStream;
            WebResponse response = request.GetResponse();
            dataStream = response.GetResponseStream();
            StreamReader reader = new StreamReader(dataStream);
            string responseFromServer = reader.ReadToEnd();
            reader.Close();
            dataStream.Close();
            response.Close();
            return responseFromServer;

        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
            faculties_id.Clear();
            comboBox2.Items.Clear();
            int uniId=int.Parse(universities_id[comboBox1.SelectedIndex].ToString());
            string responseFromServer = pigonUniApi("http://pigon.ws/university/faculties?university_id=" + uniId);
            List<Query> faculties = (List<Query>)JsonConvert.DeserializeObject(responseFromServer, typeof(List<Query>));
            foreach (Query obj in faculties)
            {
                comboBox2.Items.Add(obj.name);
                faculties_id.Add(obj.id);
            }
        }

        private void comboBox2_SelectedIndexChanged(object sender, EventArgs e)
        {
            comboBox3.Items.Clear();
            int fakulteId = int.Parse(faculties_id[comboBox2.SelectedIndex].ToString());            
            string responseFromServer = pigonUniApi("http://pigon.ws/university/departments?faculty_id=" + fakulteId);
            List<Query> departments = (List<Query>)JsonConvert.DeserializeObject(responseFromServer, typeof(List<Query>));
            foreach (Query obj in departments)
            {
                comboBox3.Items.Add(obj.name);
            }
        }
    }
}