HttpClient.cs (ver 2)

// HttpClient.cs (ver 2)
// ver 1, at http://www.player.idv.tw/prog/index.php/HttpClient.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Net;
using System.Net.Cache;
using System.Text;
using System.Web;

namespace Internet
{
    public class HttpClient
    {
        private bool _AllowAutoRedirect = false;

        private bool _AllowCookie = false;

        private HttpRequestCachePolicy _CachePolicy = null;

        private string _ContentType;

        private CookieCollection _Cookies = null;

        private ICredentials _Credentials = null;

        private bool _KeepAlive = false;

        private WebProxy _Proxy = null;

        private long[] _Range = null;

        private string _Referer = null;

        private Dictionary<string, string> _RequestHeaders = null;

        private WebHeaderCollection _ResponseHeaders = null;

        private MemoryStream _ResponseStream = null;

        private string _ResponseText = null;

        private HttpStatusCode _StatusCode = HttpStatusCode.OK;

        private Encoding _TextEncoding = null;

        private int _Timeout = 10000;

        private string _UserAgent = null;

        public HttpClient()
        {
        }

        public bool AllowAutoRedirect
        {
            set { _AllowAutoRedirect = value; }
        }

        public bool AllowCookie
        {
            get { return _AllowCookie; }
            set { _AllowCookie = value; }
        }

        public HttpRequestCachePolicy CachePolicy
        {
            set { _CachePolicy = value; }
        }

        public string ContentType
        {
            get { return _ContentType; }
        }

        public CookieCollection Cookies
        {
            get
            {
                if (_AllowCookie)
                    return _Cookies;
                return null;
            }
        }

        public ICredentials Credentials
        {
            get { return _Credentials; }
            set { _Credentials = value; }
        }

        public bool KeepAlive
        {
            set { _KeepAlive = value; }
        }

        public string Proxy
        {
            set
            {
                if (string.IsNullOrEmpty(value))
                    _Proxy = null;
                else
                    _Proxy = new WebProxy(value);
            }
        }

        public string Referer
        {
            set { _Referer = value; }
        }

        public Dictionary<string, string> RequestHeaders
        {
            get
            {
                if (_RequestHeaders == null)
                    _RequestHeaders = new Dictionary<string, string>();
                return _RequestHeaders;
            }
        }

        public WebHeaderCollection ResponseHeaders
        {
            get { return _ResponseHeaders; }
        }

        public MemoryStream ResponseStream
        {
            get { return _ResponseStream; }
        }

        public string ResponseText
        {
            get { return _ResponseText; }
        }

        public HttpStatusCode StatusCode
        {
            get { return _StatusCode; }
        }

        public Encoding TextEncoding
        {
            get
            {
                if (_TextEncoding == null)
                    _TextEncoding = Encoding.Default;
                return _TextEncoding;
            }
            set { _TextEncoding = value; }
        }

        public int Timeout
        {
            get { return _Timeout; }
            set { _Timeout = value; }
        }

        public string UserAgent
        {
            set { _UserAgent = value; }
        }

        public HttpStatusCode Get(string strUrl)
        {
            try
            {
                Uri uri = new Uri(strUrl);
                HttpWebRequest hwReq = WebRequest.Create(uri) as HttpWebRequest;

                if (_CachePolicy != null)
                    hwReq.CachePolicy = _CachePolicy;

                if (_Proxy != null)
                    hwReq.Proxy = _Proxy;

                if (_UserAgent != null)
                    hwReq.UserAgent = _UserAgent;

                hwReq.Method = "GET";
                hwReq.AllowAutoRedirect = _AllowAutoRedirect;
                hwReq.KeepAlive = _KeepAlive;
                hwReq.Timeout = _Timeout;

                if (_Range != null)
                    hwReq.AddRange(_Range[0], _Range[1]);

                if (_Referer != null)
                    hwReq.Referer = _Referer;

                // Add authentication to request
                if (_Credentials != null)
                    hwReq.Credentials = _Credentials;

                if (_RequestHeaders != null)
                {
                    foreach (string key in _RequestHeaders.Keys)
                    {
                        hwReq.Headers.Add(key, _RequestHeaders[key]);
                    }
                }

                if (_AllowCookie)
                    hwReq.CookieContainer = new CookieContainer();

                return ProcessRequest(hwReq);
            }
            catch (WebException ex)
            {
                switch (ex.Status)
                {
                    case WebExceptionStatus.ProtocolError:
                        if (ex.Response != null)
                            _StatusCode = ((HttpWebResponse)ex.Response).StatusCode;
                        break;

                    case WebExceptionStatus.Timeout:
                        _StatusCode = HttpStatusCode.RequestTimeout;
                        break;

                    default:
                        throw ex;
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }
            return _StatusCode;
        }

        public HttpStatusCode Post(string strUrl, Dictionary<string, string> postData)
        {
            try
            {
                Uri uri = new Uri(strUrl);
                HttpWebRequest hwReq = WebRequest.Create(uri) as HttpWebRequest;

                if (_CachePolicy != null)
                    hwReq.CachePolicy = _CachePolicy;

                if (_Proxy != null)
                    hwReq.Proxy = _Proxy;

                if (_UserAgent != null)
                    hwReq.UserAgent = _UserAgent;

                hwReq.Method = "POST";
                hwReq.AllowAutoRedirect = _AllowAutoRedirect;
                hwReq.KeepAlive = _KeepAlive;
                hwReq.Timeout = _Timeout;

                if (_Range != null)
                    hwReq.AddRange(_Range[0], _Range[1]);

                hwReq.ContentType = "application/x-www-form-urlencoded";

                if (_Referer != null)
                    hwReq.Referer = _Referer;

                // Add authentication to request
                if (_Credentials != null)
                    hwReq.Credentials = _Credentials;

                if (_RequestHeaders != null)
                {
                    foreach (string key in _RequestHeaders.Keys)
                    {
                        hwReq.Headers.Add(key, _RequestHeaders[key]);
                    }
                }

                if (AllowCookie)
                    hwReq.CookieContainer = new CookieContainer();

                StringBuilder data = new StringBuilder();
                string ampersand = "";
                foreach (string key in postData.Keys)
                {
                    data.Append(ampersand).Append(key).Append("=").Append(HttpUtility.UrlEncode(postData[key]));
                    ampersand = "&";
                }

                byte[] byteData = UTF8Encoding.UTF8.GetBytes(data.ToString());

                // 設定寫入內容長度
                hwReq.ContentLength = byteData.Length;

                // 寫入 POST 參數
                using (Stream postStream = hwReq.GetRequestStream())
                {
                    postStream.Write(byteData, 0, byteData.Length);
                }

                return ProcessRequest(hwReq);
            }
            catch (WebException ex)
            {
                switch (ex.Status)
                {
                    case WebExceptionStatus.ProtocolError:
                        if (ex.Response != null)
                            _StatusCode = ((HttpWebResponse)ex.Response).StatusCode;
                        break;

                    case WebExceptionStatus.Timeout:
                        _StatusCode = HttpStatusCode.RequestTimeout;
                        break;

                    default:
                        throw ex;
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }

            return _StatusCode;
        }

        public void SetCachePolicy(HttpRequestCacheLevel CacheLevel)
        {
            _CachePolicy = new HttpRequestCachePolicy(CacheLevel);
        }

        public void SetDefaultNetworkCredentials()
        {
            _Credentials = CredentialCache.DefaultNetworkCredentials;
        }

        public void SetDefaultProxy()
        {
            //過時用法?
            //_Proxy = WebProxy.GetDefaultProxy() as WebProxy;

            if (WebRequest.DefaultWebProxy != null)
            {
                WebProxy proxy = WebRequest.DefaultWebProxy as WebProxy;
                if (proxy.Address.AbsoluteUri != string.Empty)
                {
                    _Proxy = proxy;
                }
            }
        }

        public void SetNetworkCredential(string username, string password)
        {
            if ((username != null) && (password != null))
                _Credentials = new NetworkCredential(username, password);
        }

        public void SetRange(long from, long to)
        {
            if (from < to)
                _Range = new long[2] { from, to };
            else
                _Range = null;
        }
        private HttpStatusCode ProcessRequest(HttpWebRequest hwReq)
        {
            using (HttpWebResponse hwRes = hwReq.GetResponse() as HttpWebResponse)
            {
                _ContentType = hwRes.ContentType;
                if (_AllowCookie)
                    _Cookies = hwRes.Cookies;
                if (hwRes.SupportsHeaders)
                    _ResponseHeaders = hwRes.Headers;

                if ((_ContentType != null) && (_ContentType.Substring(0, 4) == "text"))
                {
                    _ResponseStream = null;
                    using (StreamReader reader = new StreamReader(hwRes.GetResponseStream(), TextEncoding))
                    {
                        _ResponseText = reader.ReadToEnd();
                    }
                }
                else
                {
                    _ResponseText = null;
                    MemoryStream content = new MemoryStream();
                    using (Stream responseStream = hwRes.GetResponseStream())
                    {
                        responseStream.CopyTo(content);
                    }
                    _ResponseStream = content;
                }
            }
            _StatusCode = HttpStatusCode.OK;
            return _StatusCode;
        }
    }
}