C#向远程地址发送数据

        static string proxyIpAddress = AppConfig.GetProxyIpAddress;
        static string proxyUserName = AppConfig.GetProxyUserName;
        static string proxyPassword = AppConfig.GetProxyPassword;

        #region Get HttpClient Return String
        /// <summary>
        /// Get HttpClient Return String
        /// </summary>
        /// <param name="apiUrl">api Url</param>
        /// <returns></returns>
        static public string GetHttpClientReturnString(string apiUrl, string reqParams)
        {
            string result = string.Empty;
            try
            {
                NetworkCredential proxyCredential = new NetworkCredential();
                proxyCredential.UserName = proxyUserName;
                proxyCredential.Password = proxyPassword;

                WebProxy proxy = new WebProxy(proxyIpAddress);
                proxy.Credentials = proxyCredential;

                var httpClientHandler = new HttpClientHandler()
                {
                    Proxy = proxy,
                };
                httpClientHandler.PreAuthenticate = true;
                httpClientHandler.UseDefaultCredentials = false;
                httpClientHandler.Credentials = proxyCredential;
                var client = new HttpClient(handler: httpClientHandler, disposeHandler: true);

                HttpContent content = new StringContent(reqParams);
                content.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue("application/json");

                var responseString = client.GetStringAsync(apiUrl);
                result = responseString.Result;
            }
            catch (Exception ex)
            {
                result = ex.Message;
            }
            return result;
        }
        #endregion

        #region Get HttpWebResponse Return String
        /// <summary>
        /// Get HttpWebResponse Return String
        /// </summary>
        /// <param name="apiUrl">api Url</param>
        /// <param name="parameters">parameters</param>
        /// <param name="contentType">contentType default value is application/x-www-form-urlencoded</param>
        /// <param name="methord">request methord default value is POST</param>
        /// <param name="timeout">timeout default value is 300000</param>
        /// <returns>response string</returns>
        static public string GetHttpWebResponseReturnString(string apiUrl, Dictionary<string, object> parameters, string contentType = "application/x-www-form-urlencoded", string methord = "POST", int timeout = 300000)
        {
            string result = string.Empty;
            string responseText = string.Empty;
            try
            {
                if (string.IsNullOrEmpty(apiUrl))
                {
                    return "apiURl is null";
                }

                StringBuilder postData = new StringBuilder();
                if (parameters != null && parameters.Count > 0)
                {
                    foreach (var p in parameters)
                    {
                        if (postData.Length == 0)
                        {
                            postData.AppendFormat("{0}={1}", p.Key, p.Value);
                        }
                        else
                        {
                            postData.AppendFormat("&{0}={1}", p.Key, p.Value);
                        }
                    }
                }

                ServicePointManager.DefaultConnectionLimit = int.MaxValue;

                NetworkCredential proxyCredential = new NetworkCredential();
                proxyCredential.UserName = proxyUserName;
                proxyCredential.Password = proxyPassword;

                WebProxy proxy = new WebProxy(proxyIpAddress);
                proxy.Credentials = proxyCredential;

                HttpWebRequest myRequest = (HttpWebRequest)WebRequest.Create(apiUrl);
                myRequest.Credentials = proxyCredential;
                myRequest.Proxy = proxy;

                myRequest.Timeout = timeout;
                myRequest.ServicePoint.MaxIdleTime = 1000;
                if (!string.IsNullOrEmpty(contentType))
                {
                    myRequest.ContentType = contentType;
                }
                myRequest.ServicePoint.Expect100Continue = false;
                myRequest.Method = methord;
                byte[] postByte = Encoding.UTF8.GetBytes(postData.ToString());
                myRequest.ContentLength = postData.Length;

                using (Stream writer = myRequest.GetRequestStream())
                {
                    writer.Write(postByte, 0, postData.Length);
                }

                using (HttpWebResponse myResponse = (HttpWebResponse)myRequest.GetResponse())
                {
                    using (StreamReader reader = new StreamReader(myResponse.GetResponseStream(), Encoding.UTF8))
                    {
                        responseText = reader.ReadToEnd();
                    }
                }
                if (!string.IsNullOrEmpty(responseText))
                {
                    result = responseText;
                }
                else
                {
                    result = "The remote service is not responding. Please try again later.";
                }
            }
            catch (Exception ex)
            {
                result = string.Format("Request exception:{0}, please try again later.", ex.Message);
            }
            return result;
        }

        #endregion