using System;
using System.Collections.Generic;
using System.Configuration;
using System.Diagnostics;
using System.IO;
using System.IO.Compression;
using System.Net;
using System.Net.Security;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using System.Text.RegularExpressions;
using System.Threading.Tasks;

namespace Common
{
    /// <summary>
    /// Http连接操作帮助类
    /// </summary>
    public class HttpHelper
    {
        #region 预定义方变量

        //默认的编码
        private Encoding _encoding = Encoding.Default;

        //Post数据编码
        private Encoding _postencoding = Encoding.Default;

        //HttpWebRequest对象用来发起请求
        private HttpWebRequest _request = null;

        //获取影响流的数据对象
        private HttpWebResponse _response = null;

        //设置本地的出口ip和端口
        private IPEndPoint _ipEndPoint = null;

        //请求错误返回码
        public string httpException = "Ex500";
        #endregion 预定义方变量


        #region 对外方法

        /// <summary>
        /// 根据相传入的数据，得到相应页面数据
        /// </summary>
        /// <param name="item">参数类对象</param>
        /// <returns>返回HttpResult类型</returns>
        public HttpResult GetData(HttpItem item)
        {
            //返回参数
            var result = new HttpResult();
            try
            {
                //准备参数
                SetRequest(item);
            }
            catch (Exception ex)
            {
                result.Cookie = string.Empty;
                result.Header = null;
                result.Html = httpException;
                result.StatusDescription = "配置参数时出错：" + ex.Message;
                //配置参数时出错
                return result;
            }

            try
            {
                //请求数据
                using (_response = (HttpWebResponse)_request.GetResponse())
                {
                    GetData(item, result);
                }
            }
            catch (WebException ex)
            {
                if (ex.Response != null)
                {
                    using (_response = (HttpWebResponse)ex.Response)
                    {
                        GetData(item, result);
                    }
                }
                else
                {
                    result.Html = httpException;
                }
            }
            catch (Exception ex)
            {
                result.Html = httpException;
            }
            if (item.IsToLower)
                result.Html = result.Html.ToLower();

            return result;
        }

       
       


       

      


        #endregion Public

        #region GetData

        /// <summary>
        /// 获取数据的并解析的方法
        /// </summary>
        /// <param name="item"></param>
        /// <param name="result"></param>
        private void GetData(HttpItem item, HttpResult result)
        {
            #region base

            //获取StatusCode
            result.StatusCode = _response.StatusCode;
            //获取StatusDescription
            result.StatusDescription = _response.StatusDescription;
            //获取最后访问的URl
            result.ResponseUri = _response.ResponseUri.ToString();
            //获取Headers
            result.Header = _response.Headers;
            //获取CookieCollection
            if (_response.Cookies != null) result.CookieCollection = _response.Cookies;
            //获取set-cookie
            if (_response.Headers["set-cookie"] != null) result.Cookie = _response.Headers["set-cookie"];

            #endregion base

            #region byte

            //处理网页Byte
            byte[] responseByte = GetByte();

            #endregion byte

            #region Html

            if (responseByte != null && responseByte.Length > 0)
            {
                //设置编码
                SetEncoding(item, result, responseByte);
                //得到返回的HTML
                result.Html = item.TranslationEncoding.GetString(responseByte);
            }
            else
            {
                //没有返回任何Html代码
                result.Html = string.Empty;
            }

            #endregion Html
        }


        /// <summary>
        /// 设置编码
        /// </summary>
        /// <param name="item">HttpItem</param>
        /// <param name="result">HttpResult</param>
        /// <param name="responseByte">byte[]</param>
        private void SetEncoding(HttpItem item, HttpResult result, byte[] responseByte)
        {
            //是否返回Byte类型数据
            if (item.ResultType == ResultType.Byte) result.ResultByte = responseByte;
            //从这里开始我们要无视编码了
            //if (_encoding == null)
            //{
            //    Match meta = Regex.Match(Encoding.Default.GetString(responseByte), "<meta[^<]*charset=([^<]*)[\"']", RegexOptions.IgnoreCase);
            //    string c = string.Empty;
            //    if (meta != null && meta.Groups.Count > 0)
            //    {
            //        c = meta.Groups[1].Value.ToLower().Trim();
            //    }

            //    if (c.Length > 2)
            //    {
            //        try
            //        {
            //            _encoding = Encoding.GetEncoding(c.Replace("\"", string.Empty).Replace("'", "").Replace(";", "").Replace("iso-8859-1", "gbk").Trim());
            //        }
            //        catch
            //        {
            //            _encoding = string.IsNullOrEmpty(_response.CharacterSet) ? Encoding.UTF8 : Encoding.GetEncoding(_response.CharacterSet);
            //        }
            //    }
            //    else
            //    {
            //        _encoding = string.IsNullOrEmpty(_response.CharacterSet) ? Encoding.UTF8 : Encoding.GetEncoding(_response.CharacterSet.Replace("\"", ""));
            //    }
            //}
        }

        /// <summary>
        /// 提取网页Byte
        /// </summary>
        /// <returns></returns>
        private byte[] GetByte()
        {
            byte[] responseByte = null;
            MemoryStream stream;

            //GZIIP处理
            if (_response.ContentEncoding != null && _response.ContentEncoding.Equals("gzip", StringComparison.InvariantCultureIgnoreCase))
            {
                //开始读取流并设置编码方式
                stream = GetMemoryStream(new GZipStream(_response.GetResponseStream(), CompressionMode.Decompress));
            }
            else
            {
                //开始读取流并设置编码方式
                stream = GetMemoryStream(_response.GetResponseStream());
            }
            //获取Byte
            responseByte = stream.ToArray();
            stream.Close();
            return responseByte;
        }

        /// <summary>
        /// 4.0以下.net版本取数据使用
        /// </summary>
        /// <param name="streamResponse">流</param>
        private MemoryStream GetMemoryStream(Stream streamResponse)
        {
            MemoryStream stream = new MemoryStream();
            int Length = 256;
            Byte[] buffer = new Byte[Length];
            int bytesRead = streamResponse.Read(buffer, 0, Length);
            while (bytesRead > 0)
            {
                stream.Write(buffer, 0, bytesRead);
                bytesRead = streamResponse.Read(buffer, 0, Length);
            }
            return stream;
        }

        #endregion GetData

        #region SetRequest

        /// <summary>
        /// 为请求准备参数
        /// </summary>
        ///<param name="item">参数列表</param>
        private void SetRequest(HttpItem item)
        {
            // 验证证书
            SetCer(item);
            _request.Headers.Add(HttpRequestHeader.AcceptLanguage, item.AcceptLanguage);
            if (item.IPEndPoint != null)
            {
                _ipEndPoint = item.IPEndPoint;
                //设置本地的出口ip和端口
                _request.ServicePoint.BindIPEndPointDelegate = new BindIPEndPoint(BindIPEndPointCallback);
            }

            //设置Header参数
            if (item.Header != null && item.Header.Count > 0)
            {
                foreach (string key in item.Header.AllKeys)
                {
                    _request.Headers.Add(key, item.Header[key]);
                }
            }

            // 设置代理
            SetProxy(item);

            if (item.ProtocolVersion != null)
            {
                //获取或设置用于请求的 HTTP 版本
                _request.ProtocolVersion = item.ProtocolVersion;
            }
            //获取或设置一个 System.Boolean 值，该值确定是否使用 100-Continue 行为
            _request.ServicePoint.Expect100Continue = item.Expect100Continue;
            //请求方式Get或者Post
            _request.Method = item.Method;
            //请求超时时间
            _request.Timeout = item.Timeout;
            //是否建立永久链接
            _request.KeepAlive = item.KeepAlive;
            //写入数据超时时间
            _request.ReadWriteTimeout = item.ReadWriteTimeout;

            if (item.IfModifiedSince != null)
            {
                //获取或设置 If-Modified-Since HTTP 标头的值
                _request.IfModifiedSince = Convert.ToDateTime(item.IfModifiedSince);
            }
            //Accept
            _request.Accept = item.Accept;
            //ContentType返回类型
            string boundary = "----------------------------" + DateTime.Now.Ticks.ToString("x");
            if (item.FormData != null && item.FormData.Count > 0)
                _request.ContentType = "multipart/form-data; boundary=" + boundary;
            else
                _request.ContentType = item.ContentType;
            //UserAgent客户端的访问类型，包括浏览器版本和操作系统信息
            _request.UserAgent = item.UserAgent;
            // 编码
            _encoding = item.Encoding;
            //设置安全凭证
            _request.Credentials = item.ICredentials;
            //设置Cookie
            SetCookie(item);
            //来源地址
            _request.Referer = item.Referer;
            //是否执行跳转功能
            _request.AllowAutoRedirect = item.Allowautoredirect;

            if (item.MaximumAutomaticRedirections > 0)
            {
                //获取或设置请求将跟随的重定向的最大数目
                _request.MaximumAutomaticRedirections = item.MaximumAutomaticRedirections;
            }

            //设置Post数据
            if (item.FormData != null && item.FormData.Count > 0)
                SetFormData(item, boundary);
            else
                SetPostData(item);

            //设置最大连接
            if (item.Connectionlimit > 0)
            {
                //获取或设置此 System.Net.ServicePoint 对象上允许的最大连接数
                _request.ServicePoint.ConnectionLimit = item.Connectionlimit;
            }

        }

        /// <summary>
        /// 设置证书
        /// </summary>
        /// <param name="item"></param>
        private void SetCer(HttpItem item)
        {
            if (!string.IsNullOrEmpty(item.CerPath))
            {
                //这一句一定要写在创建连接的前面。使用回调的方法进行证书验证。
                ServicePointManager.ServerCertificateValidationCallback = new System.Net.Security.RemoteCertificateValidationCallback(CheckValidationResult);
                //初始化对像，并设置请求的URL地址
                _request = (HttpWebRequest)WebRequest.Create(item.Url);
                SetCerList(item);
                //将证书添加到请求里
                _request.ClientCertificates.Add(new X509Certificate(item.CerPath));
            }
            else
            {
                //初始化对像，并设置请求的URL地址
                _request = (HttpWebRequest)WebRequest.Create(item.Url);
                SetCerList(item);
            }
        }

        /// <summary>
        /// 设置多个证书
        /// </summary>
        /// <param name="item"></param>
        private void SetCerList(HttpItem item)
        {
            if (item.ClentCertificates != null && item.ClentCertificates.Count > 0)
            {
                foreach (X509Certificate c in item.ClentCertificates)
                {
                    _request.ClientCertificates.Add(c);
                }
            }
        }

        /// <summary>
        /// 设置Cookie
        /// </summary>
        /// <param name="item">Http参数</param>
        private void SetCookie(HttpItem item)
        {
            if (!string.IsNullOrEmpty(item.Cookie)) _request.Headers[HttpRequestHeader.Cookie] = item.Cookie;
            //设置CookieCollection
            if (item.ResultCookieType == ResultCookieType.CookieCollection)
            {
                _request.CookieContainer = new CookieContainer();
                if (item.CookieCollection != null && item.CookieCollection.Count > 0)
                    _request.CookieContainer.Add(item.CookieCollection);
            }
        }

        /// <summary>
        /// 设置Post数据
        /// </summary>
        /// <param name="item">Http参数</param>
        private void SetPostData(HttpItem item)
        {
            //验证在得到结果时是否有传入数据
            if (!_request.Method.Trim().ToLower().Contains("get"))
            {
                if (item.PostEncoding != null)
                {
                    _postencoding = item.PostEncoding;
                }

                byte[] buffer = null;
                //写入Byte类型
                if (item.PostDataType == PostDataType.Byte && item.PostdataByte != null && item.PostdataByte.Length > 0)
                {
                    //验证在得到结果时是否有传入数据
                    buffer = item.PostdataByte;
                }//写入文件
                else if (item.PostDataType == PostDataType.FilePath && !string.IsNullOrEmpty(item.Postdata))
                {
                    StreamReader r = new StreamReader(item.Postdata, _postencoding);
                    buffer = _postencoding.GetBytes(r.ReadToEnd());
                    r.Close();
                } //写入字符串
                else if (!string.IsNullOrEmpty(item.Postdata))
                {
                    buffer = _postencoding.GetBytes(item.Postdata);
                }

                if (buffer != null)
                {
                    _request.ContentLength = buffer.Length;
                    _request.GetRequestStream().Write(buffer, 0, buffer.Length);
                }
                else
                {
                    _request.ContentLength = 0;
                }
            }
        }
        private void SetFormData(HttpItem item, string boundary)
        {
            //验证在得到结果时是否有传入数据
            if (!_request.Method.Trim().ToLower().Contains("get"))
            {
                if (item.PostEncoding != null)
                {
                    _postencoding = item.PostEncoding;
                }
                MemoryStream stream = new MemoryStream();
                string format = "--" + boundary + "\r\nContent-Disposition:form-data;name=\"{0}\"\r\n\r\n{1}\r\n";    //自带项目分隔符
                foreach (string key in item.FormData.Keys)
                {
                    string s = string.Format(format, key, item.FormData[key]);
                    byte[] data = Encoding.UTF8.GetBytes(s);
                    stream.Write(data, 0, data.Length);
                }

                byte[] foot_data = Encoding.UTF8.GetBytes("--" + boundary + "--\r\n");      //项目最后的分隔符字符串需要带上--  
                stream.Write(foot_data, 0, foot_data.Length);
                _request.ContentLength = stream.Length;
                Stream requestStream = _request.GetRequestStream(); //写入请求数据
                stream.Position = 0L;
                stream.CopyTo(requestStream); //
                stream.Close();
            }
        }
        /// <summary>
        /// 设置代理
        /// </summary>
        /// <param name="item">参数对象</param>
        private void SetProxy(HttpItem item)
        {
            bool isIeProxy = false;
            if (!string.IsNullOrEmpty(item.ProxyIp))
            {
                isIeProxy = item.ProxyIp.ToLower().Contains("ieproxy");
            }
            if (!string.IsNullOrEmpty(item.ProxyIp) && !isIeProxy)
            {
                //设置代理服务器
                if (item.ProxyIp.Contains(":"))
                {
                    string[] plist = item.ProxyIp.Split(':');
                    WebProxy myProxy = new WebProxy(plist[0].Trim(), Convert.ToInt32(plist[1].Trim()))
                    {
                        //建议连接
                        Credentials = new NetworkCredential(item.ProxyUserName, item.ProxyPwd)
                    };
                    //给当前请求对象
                    _request.Proxy = myProxy;
                }
                else
                {
                    WebProxy myProxy = new WebProxy(item.ProxyIp, false)
                    {
                        //建议连接
                        Credentials = new NetworkCredential(item.ProxyUserName, item.ProxyPwd)
                    };
                    //给当前请求对象
                    _request.Proxy = myProxy;
                }
            }
            else if (isIeProxy)
            {
                //设置为IE代理
            }
            else
            {
                _request.Proxy = item.WebProxy;
            }
        }

        #endregion SetRequest

        #region private main

        /// <summary>
        /// 回调验证证书问题
        /// </summary>
        /// <param name="sender">流对象</param>
        /// <param name="certificate">证书</param>
        /// <param name="chain">X509Chain</param>
        /// <param name="errors">SslPolicyErrors</param>
        /// <returns>bool</returns>
        private bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors) { return true; }

        /// <summary>
        /// 通过设置这个属性，可以在发出连接的时候绑定客户端发出连接所使用的IP地址。
        /// </summary>
        /// <param name="servicePoint"></param>
        /// <param name="remoteEndPoint"></param>
        /// <param name="retryCount"></param>
        /// <returns></returns>
        private IPEndPoint BindIPEndPointCallback(ServicePoint servicePoint, IPEndPoint remoteEndPoint, int retryCount)
        {
            return _ipEndPoint;//端口号
        }

        #endregion private main
    }

    #region 实体类
    /// <summary>
    /// Http请求参考类
    /// </summary>
    public class HttpItem
    {


        /// <summary>
        /// 请求URL必须填写
        /// </summary>
        public string Url { get; set; }

        /// <summary>
        /// 转译编码
        /// </summary>
        public Encoding TranslationEncoding { get; set; } = Encoding.UTF8;


        /// <summary>
        /// 请求方式默认为GET方式,当为POST方式时必须设置Postdata的值
        /// </summary>
        public string Method { get; set; } = "GET";


        /// <summary>
        /// 默认请求超时时间，默认90秒
        /// </summary>
        public int Timeout { get; set; } = 90 * 1000;

        /// <summary>
        /// 默认写入Post数据超时间，默认60秒
        /// </summary>
        public int ReadWriteTimeout { get; set; } = 30 * 1000;

        /// <summary>
        ///  获取或设置一个值，该值指示是否与 Internet 资源建立持久性连接默认为true。
        /// </summary>
        public Boolean KeepAlive { get; set; } = true;

        /// <summary>
        /// 请求标头值，默认为text/html, application/xhtml+xml, */*
        /// <para>1、application/json</para>
        /// </summary>
        public string Accept { get; set; } = "text/html, application/xhtml+xml, */*";


        /// <summary>
        /// 请求返回类型，默认为text/html
        /// <para>1、application/x-www-form-urlencoded；最常见的 POST 提交数据的方式</para>
        /// <para>2、multipart/form-data；主要用于上传文件</para>
        /// <para>3、application/json；服务端消息主体是序列化后的 JSON 字符串</para>
        /// <para>4、text/xml</para>
        /// </summary>
        public string ContentType { get; set; } = "text/html";


        /// <summary>
        /// 客户端访问信息默认Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)
        /// 解读：MSIE 8.0代表IE8, Windows NT 6.1 对应操作系统 windows 7
        /// <para>1、IE各个版本典型的UserAgent如下：</para>
        /// <para>Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)</para>
        /// <para>Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 5.2)</para>
        /// <para>Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)</para>
        /// <para>Mozilla/4.0 (compatible; MSIE 5.0; Windows NT)</para>
        /// <para>2、Firefox的UserAgent如下： </para>
        /// <para>Mozilla/5.0 (Windows; U; Windows NT 5.2) Gecko/2008070208 Firefox/3.0.1</para>
        /// <para>Mozilla/5.0 (Windows; U; Windows NT 5.1) Gecko/20070309 Firefox/2.0.0.3</para>
        /// <para>Mozilla/5.0 (Windows; U; Windows NT 5.1) Gecko/20070803 Firefox/1.5.0.12</para>
        /// <para>解读：N: 表示无安全加密 I: 表示弱安全加密 U: 表示强安全加密</para>
        /// <para>3、Opera典型的UserAgent如下：</para>
        /// <para>Opera/9.27 (Windows NT 5.2; U; zh-cn)</para>
        /// <para>Opera/8.0 (Macintosh; PPC Mac OS X; U; en)</para>
        /// <para>Mozilla/5.0 (Macintosh; PPC Mac OS X; U; en) Opera 8.0 </para>
        /// <para>4、Safari典型的UserAgent如下：</para>
        /// <para>Mozilla/5.0 (Windows; U; Windows NT 5.2) AppleWebKit/525.13 (KHTML, like Gecko) Version/3.1 Safari/525.13</para>
        ///  <para>Mozilla/5.0 (iPhone; U; CPU like Mac OS X) AppleWebKit/420.1 (KHTML, like Gecko) Version/3.0 Mobile/4A93 Safari/419.3</para>
        /// <para>5、Chrome的UserAgent如下：</para>
        /// <para>Mozilla/5.0 (Windows; U; Windows NT 5.2) AppleWebKit/525.13 (KHTML, like Gecko) Chrome/0.2.149.27 Safari/525.13 </para>
        /// <para>6、Navigator的UserAgent如下：</para>
        /// <para>Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.12) Gecko/20080219 Firefox/2.0.0.12 Navigator/9.0.0.6</para>
        /// <para>7、安卓 原生浏览器</para>
        /// <para>Mozilla/5.0 (Linux; U; Android 4.0.3; zh-cn; M032 Build/IML74K) AppleWebKit/534.30 (KHTML, like Gecko) Version/4.0 Mobile Safari/534.30</para>
        /// <para>8、iPhone Safria</para>
        /// <para>Mozilla/5.0 (iPhone; CPU iPhone OS 5_1_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9B206 Safari/7534.48.3</para>
        /// <para>9、塞班 自带浏览器</para>
        /// <para>Nokia5320/04.13 (SymbianOS/9.3; U; Series60/3.2 Mozilla/5.0; Profile/MIDP-2.1 Configuration/CLDC-1.1 ) AppleWebKit/413 (KHTML, like Gecko) Safari/413</para>
        /// </summary>
        public string UserAgent { get; set; } = "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)";

        /// <summary>
        /// 返回数据编码默认为NUll,可以自动识别,一般为utf-8,gbk,gb2312
        /// </summary>
        public Encoding Encoding { get; set; } = null;

        /// <summary>
        /// Post的数据类型
        /// </summary>
        public PostDataType PostDataType { get; set; } = PostDataType.String;

        /// <summary>
        /// Post请求时要发送的字符串Post数据
        /// </summary>
        public string Postdata { get; set; }

        /// <summary>
        /// 表单提交数据
        /// </summary>
        public Dictionary<string, string> FormData { get; set; }



        /// <summary>
        /// Post请求时要发送的Byte类型的Post数据
        /// </summary>
        public byte[] PostdataByte { get; set; } = null;


        /// <summary>
        /// 设置代理对象，不想使用IE默认配置就设置为Null，而且不要设置ProxyIp
        /// </summary>
        public WebProxy WebProxy { get; set; }


        /// <summary>
        /// Cookie对象集合
        /// </summary>
        public CookieCollection CookieCollection { get; set; } = null;


        /// <summary>
        /// 请求时的Cookie
        /// </summary>
        public string Cookie { get; set; }

        private string _referer = string.Empty;

        /// <summary>
        /// 来源地址，上次访问地址
        /// </summary>
        public string Referer { get; set; }

        /// <summary>
        /// 证书绝对路径
        /// </summary>
        public string CerPath { get; set; }

        /// <summary>
        /// 是否设置为全文小写，默认为不转化
        /// </summary>
        public Boolean IsToLower { get; set; } = false;

        /// <summary>
        /// 支持跳转页面，查询结果将是跳转后的页面，默认是不跳转
        /// </summary>
        public bool Allowautoredirect { get; set; } = false;


        /// <summary>
        /// 最大连接数
        /// </summary>
        public int Connectionlimit { get; set; } = 1024;

        /// <summary>
        /// 代理Proxy 服务器用户名
        /// </summary>
        public string ProxyUserName { get; set; }

        private string _proxypwd = string.Empty;

        /// <summary>
        /// 代理 服务器密码
        /// </summary>
        public string ProxyPwd { get; set; }


        /// <summary>
        /// 代理 服务IP ,如果要使用IE代理就设置为ieproxy
        /// </summary>
        public string ProxyIp { get; set; }

        /// <summary>
        /// 设置返回类型String和Byte
        /// </summary>
        public ResultType ResultType { get; set; } = ResultType.String;


        /// <summary>
        /// header对象
        /// </summary>
        public WebHeaderCollection Header { get; set; } = new WebHeaderCollection();

        /// <summary>
        //  获取或设置用于请求的 HTTP 版本。返回结果:用于请求的 HTTP 版本。默认为 System.Net.HttpVersion.Version11。
        /// </summary>
        public Version ProtocolVersion { get; set; } = System.Net.HttpVersion.Version11;

        /// <summary>
        ///  获取或设置一个 System.Boolean 值，该值确定是否使用 100-Continue 行为。如果 POST 请求需要 100-Continue 响应，则为 true；否则为 false。默认值为 true。
        /// </summary>
        public Boolean Expect100Continue { get; set; } = false;

        /// <summary>
        /// 设置509证书集合
        /// </summary>
        public X509CertificateCollection ClentCertificates { get; set; }

        /// <summary>
        /// 设置或获取Post参数编码,默认的为Default编码
        /// </summary>
        public Encoding PostEncoding { get; set; } = Encoding.Default;

        /// <summary>
        /// Cookie返回类型,默认的是只返回字符串类型
        /// </summary>
        public ResultCookieType ResultCookieType { get; set; } = ResultCookieType.String;


        /// <summary>
        /// 获取或设置请求的身份验证信息。
        /// </summary>
        public ICredentials ICredentials { get; set; } = CredentialCache.DefaultCredentials;

        /// <summary>
        /// 设置请求将跟随的重定向的最大数目
        /// </summary>
        private int _maximumAutomaticRedirections;

        public int MaximumAutomaticRedirections { get; set; }

        /// <summary>
        /// 获取和设置IfModifiedSince，默认为当前日期和时间
        /// </summary>
        public DateTime? IfModifiedSince { get; set; } = null;

        /// <summary>
        /// Accept-Language
        /// </summary>
        public string AcceptLanguage { get; set; } = "zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2";

        #region ip-port


        /// <summary>
        /// 设置本地的出口ip和端口
        /// </summary>]
        /// <example>
        ///item.IPEndPoint = new IPEndPoint(IPAddress.Parse("192.168.1.1"),80);
        /// </example>
        public IPEndPoint IPEndPoint { get; set; } = null;

        #endregion ip-port
    }

    /// <summary>
    /// Http返回参数类
    /// </summary>
    public class HttpResult
    {
        private string _cookie;

        /// <summary>
        /// Http请求返回的Cookie
        /// </summary>
        public string Cookie { get; set; }


        /// <summary>
        /// Cookie对象集合
        /// </summary>
        public CookieCollection CookieCollection { get; set; }

        /// <summary>
        /// 返回的String类型数据 只有ResultType.String时才返回数据，其它情况为空
        /// </summary>
        public string Html { get; set; }

        /// <summary>
        /// 返回的Byte数组 只有ResultType.Byte时才返回数据，其它情况为空
        /// </summary>
        public byte[] ResultByte { get; set; }

        /// <summary>
        /// header对象
        /// </summary>
        public WebHeaderCollection Header { get; set; }

        /// <summary>
        /// 返回状态说明
        /// </summary>
        public string StatusDescription { get; set; }


        /// <summary>
        /// 返回状态码,默认为OK
        /// </summary>
        public HttpStatusCode StatusCode { get; set; }

        /// <summary>
        /// 最后访问的URl
        /// </summary>
        public string ResponseUri { get; set; }

        /// <summary>
        /// 获取重定向的URl
        /// </summary>
        public string RedirectUrl
        {
            get
            {
                try
                {
                    if (Header != null && Header.Count > 0)
                    {
                        string baseurl = Header["location"].ToString().Trim();
                        string locationurl = baseurl.ToLower();
                        if (!string.IsNullOrWhiteSpace(locationurl))
                        {
                            bool b = locationurl.StartsWith("http://") || locationurl.StartsWith("https://");
                            if (!b)
                            {
                                baseurl = new Uri(new Uri(ResponseUri), baseurl).AbsoluteUri;
                            }
                        }
                        return baseurl;
                    }
                }
                catch { }
                return string.Empty;
            }
        }
    }

    /// <summary>
    /// 返回类型
    /// </summary>
    public enum ResultType
    {
        /// <summary>
        /// 表示只返回字符串 只有Html有数据
        /// </summary>
        String,

        /// <summary>
        /// 表示返回字符串和字节流 ResultByte和Html都有数据返回
        /// </summary>
        Byte
    }

    /// <summary>
    /// Post的数据格式默认为string
    /// </summary>
    public enum PostDataType
    {
        /// <summary>
        /// 字符串类型，这时编码Encoding可不设置
        /// </summary>
        String,

        /// <summary>
        /// Byte类型，需要设置PostdataByte参数的值编码Encoding可设置为空
        /// </summary>
        Byte,

        /// <summary>
        /// 传文件，Postdata必须设置为文件的绝对路径，必须设置Encoding的值
        /// </summary>
        FilePath
    }

    /// <summary>
    /// Cookie返回类型
    /// </summary>
    public enum ResultCookieType
    {
        /// <summary>
        /// 只返回字符串类型的Cookie
        /// </summary>
        String,

        /// <summary>
        /// CookieCollection格式的Cookie集合同时也返回String类型的cookie
        /// </summary>
        CookieCollection
    }
    #endregion
}