HttpClient封装

public enum HttpMethod { Get, Post }


    /// <summary>HttpClient</summary>   
    public class HttpClient
    {
        public Encoding encoding { get; set; }

        public HttpClient()
        {
            this.encoding = Encoding.Default;
        }
        public HttpClient(Encoding encoding)
        {
            this.encoding = encoding;
        }

        /// <summary>
        /// Get请求
        /// </summary>
        public HttpResponse get(string url, HttpParameter[] parameters = null, Dictionary<string, string> headers = null)
        {
            return this.request(url, HttpMethod.Get, parameters, headers);
        }

        /// <summary>
        /// Post请
        /// </summary>
        public HttpResponse post(string url, HttpParameter[] parameters = null, Dictionary<string, string> headers = null, string postData = null)
        {
            return this.request(url, HttpMethod.Post, parameters, headers, postData);
        }

        /// <summary>
        /// 请求
        /// </summary>
        public HttpResponse request(string url, HttpMethod method = HttpMethod.Get, HttpParameter[] parameters = null, Dictionary<string, string> headers = null, string postData = null, string contentType = null)
        {
            if (method == HttpMethod.Get && parameters != null)
                url += (url.IndexOf("?") == -1 ? "?" : "&") + this.buildStringParameters(parameters);

            HttpWebRequest http = WebRequest.Create(url) as HttpWebRequest;
            http.ServicePoint.Expect100Continue = false;
            http.UserAgent = "Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.0)";

            if (headers != null)
            {
                foreach (var key in headers.Keys)
                {
                    http.Headers[key] = headers[key];
                }
            }

            switch (method)
            {
                case HttpMethod.Get:
                    {
                        http.Method = "GET";
                        break;
                    }
                case HttpMethod.Post:
                    {
                        http.Method = "POST";
                        if (!string.IsNullOrEmpty(contentType))
                        {
                            http.ContentType = contentType;
                            using (StreamWriter request = new StreamWriter(http.GetRequestStream()))
                            {
                                try
                                {
                                    if (postData == null)
                                        request.Write(this.buildStringParameters(parameters));
                                    else
                                        request.Write(postData);
                                }
                                finally
                                {
                                    request.Close();
                                }
                            }
                        }
                        else
                        {
                            if (parameters != null && parameters.Count(p => p.isBinary) > 0)
                            {
                                string boundary = this.getBoundary();
                                http.ContentType = string.Format("multipart/form-data; boundary={0}", boundary);
                                http.AllowWriteStreamBuffering = true;
                                using (Stream request = http.GetRequestStream())
                                {
                                    try
                                    {
                                        var raw = this.buildBinaryParameters(boundary, parameters);
                                        request.Write(raw, 0, raw.Length);
                                    }
                                    finally
                                    {
                                        request.Close();
                                    }
                                }
                            }
                            else
                            {
                                http.ContentType = "application/x-www-form-urlencoded";

                                using (StreamWriter request = new StreamWriter(http.GetRequestStream()))
                                {
                                    try
                                    {
                                        if (postData == null)
                                            request.Write(this.buildStringParameters(parameters));
                                        else
                                            request.Write(postData);
                                    }
                                    finally
                                    {
                                        request.Close();
                                    }
                                }
                            }
                        }
                        break;
                    }
            }


            var httpResponse = new HttpResponse();
            try
            {
                using (WebResponse response = http.GetResponse())
                {
                    using (StreamReader reader = new StreamReader(response.GetResponseStream(), this.encoding))
                    {
                        httpResponse.content = reader.ReadToEnd().Trim();
                        reader.Close();
                    }
                    response.Close();
                }
            }
            catch (WebException e)
            {
                httpResponse.status = e.Status;
                httpResponse.Message = e.Message;
                httpResponse.StackTrace = e.StackTrace;
                httpResponse.TotalMessage=e.Status+"======"+ e.Message+"=====" + e.StackTrace;
            }

            return httpResponse;
        }

        /// <summary>
        /// hash值
        /// </summary>
        private string getBoundary()
        {
            string pattern = "abcdefghijklmnopqrstuvwxyz0123456789";
            StringBuilder boundaryBuilder = new StringBuilder();
            Random rnd = new Random();
            for (int i = 0; i < 10; i++)
            {
                var index = rnd.Next(pattern.Length);
                boundaryBuilder.Append(pattern[index]);
            }
            return boundaryBuilder.ToString();
        }

        /// <summary>
        /// 生成字符参数
        /// </summary>
        private string buildStringParameters(HttpParameter[] parameters)
        {
            if (parameters == null) return "";

            var s = new StringBuilder("");
            bool first = true;
            foreach (var item in parameters)
            {
                if (first) first = false;
                else s.Append("&");

                var value = string.Format("{0}", item.value);
                s.Append(Uri.EscapeDataString(item.name)).Append("=").Append(Uri.EscapeDataString(value));
            }
            return s.ToString();
        }

        /// <summary>
        /// 生成二进制参数
        /// </summary>
        /// <param name="boundary"></param>
        /// <param name="parameters">参数</param>
        /// <returns></returns>
        private byte[] buildBinaryParameters(string boundary, params HttpParameter[] parameters)
        {
            List<HttpParameter> pairs = new List<HttpParameter>(parameters);
            MemoryStream buff = new MemoryStream();

            byte[] headerBuff = Encoding.ASCII.GetBytes(string.Format("\r\n--{0}\r\n", boundary));
            byte[] footerBuff = Encoding.ASCII.GetBytes(string.Format("\r\n--{0}--", boundary));

            StringBuilder contentBuilder = new StringBuilder();

            foreach (HttpParameter p in pairs)
            {
                if (!p.isBinary)
                {
                    var value = string.Format("{0}", p.value);
                    if (string.IsNullOrEmpty(value))
                    {
                        continue;
                    }


                    buff.Write(headerBuff, 0, headerBuff.Length);
                    byte[] dispositonBuff = Encoding.UTF8.GetBytes(string.Format("content-disposition: form-data; name=\"{0}\"\r\n\r\n{1}", p.name, p.value.ToString()));
                    buff.Write(dispositonBuff, 0, dispositonBuff.Length);

                }
                else
                {
                    buff.Write(headerBuff, 0, headerBuff.Length);
                    string headerTemplate = "Content-Disposition: form-data; name=\"{0}\"; filename=\"{1}\"\r\nContent-Type: \"image/unknow\"\r\nContent-Transfer-Encoding: binary\r\n\r\n";
                    byte[] fileBuff = System.Text.Encoding.UTF8.GetBytes(string.Format(headerTemplate, p.name, string.Format("upload{0}", BitConverter.ToInt64(Guid.NewGuid().ToByteArray(), 0))));
                    buff.Write(fileBuff, 0, fileBuff.Length);
                    byte[] file = (byte[])p.value;
                    buff.Write(file, 0, file.Length);

                }
            }

            buff.Write(footerBuff, 0, footerBuff.Length);
            buff.Position = 0;

            byte[] contentBuff = new byte[buff.Length];
            buff.Read(contentBuff, 0, contentBuff.Length);
            buff.Close();
            buff.Dispose();
            return contentBuff;
        }
    }