HTTPInterface

using System;
using System.Net;
using System.IO;
using System.Text;

public class HttpInterface
{
    private CookieContainer local_cookies = new CookieContainer();
    private string local_user_agent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/535.11 (KHTML, like Gecko) Chrome/17.0.963.79 Safari/535.11";
    private bool local_allow_auto_redirect = true;
    private bool local_keep_cookies = true;
    private WebProxy local_proxy = null;
    private int local_timeout = 100000;
    private bool local_ajax = false;
    private string local_error = string.Empty;

    #region Settings
    public string user_agent
    {
        get
        {
            return this.local_user_agent;
        }
        set
        {
            this.local_user_agent = value;
        }
    }

    public string proxy
    {
        get
        {
            return this.local_proxy.Address.Host + ":" + this.local_proxy.Address.Port;
        }
        set
        {
            if (valid_proxy(value))
            {
                string[] splitted = value.Split(':');
                this.local_proxy = new WebProxy(splitted[0], Convert.ToInt32(splitted[1]));
            }
        }
    }

    public int timeout
    {
        get
        {
            return this.local_timeout;
        }
        set
        {
            this.local_timeout = value;
        }
    }

    public bool allow_auto_redirect
    {
        get
        {
            return this.local_allow_auto_redirect;
        }
        set
        {
            this.local_allow_auto_redirect = value;
        }
    }

    public bool keep_cookies
    {
        get
        {
            return this.local_keep_cookies;
        }
        set
        {
            this.local_keep_cookies = value;
        }
    }

    public bool ajax
    {
        get
        {
            return this.local_ajax;
        }
        set
        {
            this.local_ajax = value;
        }
    }
    #endregion

    #region Main
    public string request(string method, string url, string data, string referer)
    {
        this.local_error = string.Empty;
        if (valid_url(url))
        {
            HttpWebResponse response = null;
            StreamReader stream_reader = null;
            try
            {
                HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(url);
                request.Method = (method = method.ToUpper());
                request.Referer = referer;

                request.AllowAutoRedirect = this.local_allow_auto_redirect;
                request.CookieContainer = this.local_cookies;
                request.UserAgent = this.local_user_agent;
                request.Timeout = this.local_timeout;
                request.Proxy = this.local_proxy;
                if (this.local_ajax)
                {
                    request.Headers.Add("X-Requested-With", "XMLHttpRequest");
                }
                if (method.Equals("POST"))
                {
                    request.ContentType = "application/x-www-form-urlencoded";
                    request.ContentLength = data.Length;
                    byte[] bytes = Encoding.ASCII.GetBytes(data);
                    if (bytes.Length == data.Length)
                    {
                        Stream data_stream = request.GetRequestStream();
                        data_stream.Write(bytes, 0, bytes.Length);
                        data_stream.Close();
                    }
                }
                response = (HttpWebResponse)request.GetResponse();
                foreach (Cookie cookie in response.Cookies)
                {
                    this.local_cookies.Add(cookie);
                }
                stream_reader = new StreamReader(response.GetResponseStream());
                return stream_reader.ReadToEnd();
            }
            catch (Exception ex)
            {
                this.local_error = ex.StackTrace;
            }
            finally
            {
                if (response != null)
                {
                    response.Close();
                }
                if (stream_reader != null)
                {
                    stream_reader.Close();
                }
            }
        }
        else
        {
            this.local_error = "The URL '" + url + "' is invalid.";
        }
        return string.Empty;
    }

    public string get(string url)
    {
        return this.request("GET", url, string.Empty, string.Empty);
    }

    public string get(string url, string referal)
    {
        return this.request("GET", url, string.Empty, referal);
    }

    public string post(string url, string data)
    {
        return this.request("POST", url, data, string.Empty);
    }

    public string post(string url, string data, string referal)
    {
        return this.request("POST", url, data, referal);
    }
    #endregion

    #region Validate
    public bool valid_url(string url)
    {
        Uri create;
        return Uri.TryCreate(url, UriKind.RelativeOrAbsolute, out create);
    }

    public bool valid_proxy(string proxy)
    {
        string[] splitted = proxy.Split(':');
        if (splitted.Length == 2 && valid_url(splitted[0]))
        {
            try
            {

                new WebProxy(splitted[0], Convert.ToInt32(splitted[1]));
                return true;
            }
            catch { }
        }
        return false;
    }
    #endregion
}