申公前幾日和一個客戶做系統對接，以前和客戶對接一般採用webservice或者json 解析的方式，直接呼叫標準解析就可以。沒想到客戶用“請求響應模式”，直接訪問人家的介面地址取資料，無奈打造一個通用的訪問類吧

參考MSDN的解釋：

HttpWebRequest類：提供WebRequest類的Http特定的實現。 

HttpWebRequest 類對 WebRequest 中定義的屬性和方法提供支援，也對使使用者能夠直接與使用 HTTP 的伺服器互動的附加屬性和方法提供支援。 

不要使用建構函式建立HttpWebRequest例項，請使用System.Net.WebRequest.Create(URI uriString)來建立例項，如果URI是Http://或Https://， 

好了，直接上程式碼：

using System.Net;
using System.IO;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;
using System.Windows.Forms;



/*    
 * 作者：申公
 * 日期：
 * 說明：此類提供http，POST和GET訪問遠端介面
 * */
namespace ZJS.EDI.Business.HttpUtility
{
    /// <summary>
    /// 有關HTTP請求的輔助類 
    /// </summary>
    public class HttpWebResponseUtility
    {

        private static readonly string DefaultUserAgent = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322; .NET CLR 2.0.50727)";//瀏覽器
        private static Encoding requestEncoding = System.Text.Encoding.UTF8;//字符集

        /// <summary>  
        /// 建立GET方式的HTTP請求  
        /// </summary>  
        /// <param name="url">請求的URL</param>  
        /// <param name="timeout">請求的超時時間</param>  
        /// <param name="userAgent">請求的客戶端瀏覽器資訊，可以為空</param>  
        /// <param name="cookies">隨同HTTP請求傳送的Cookie資訊，如果不需要身份驗證可以為空</param>  
        /// <returns></returns>  
        public static HttpWebResponse CreateGetHttpResponse(string url, int? timeout, string userAgent, CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }
            HttpWebRequest request = WebRequest.Create(url) as HttpWebRequest;
            request.Method = "GET";
            request.UserAgent = DefaultUserAgent;
            if (!string.IsNullOrEmpty(userAgent))
            {
                request.UserAgent = userAgent;
            }
            if (timeout.HasValue)
            {
                request.Timeout = timeout.Value;
            }
            if (cookies != null)
            {
                request.CookieContainer = new CookieContainer();
                request.CookieContainer.Add(cookies);
            }
            return request.GetResponse() as HttpWebResponse;
        }


        /// <summary>  
        /// 建立POST方式的HTTP請求
        /// </summary>  
        /// <param name="url">請求的URL</param>  
        /// <param name="parameters">隨同請求POST的引數名稱及引數值字典</param>  
        /// <param name="cookies">隨同HTTP請求傳送的Cookie資訊，如果不需要身份驗證可以為空</param>  
        /// <returns></returns>
        public static HttpWebResponse CreatePostHttpResponse(string url, string parameters, CookieCollection cookies)
        {
            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }

            HttpWebRequest request = null;
            Stream stream = null;//用於傳引數的流

            try
            {
                //如果是傳送HTTPS請求  
                if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
                {
                    ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
                    request = WebRequest.Create(url) as HttpWebRequest;
                    //建立證書檔案
                    System.Security.Cryptography.X509Certificates.X509Certificate objx509 = new System.Security.Cryptography.X509Certificates.X509Certificate(Application.StartupPath + @"\\licensefile\zjs.cer");
                    //新增到請求裡
                    request.ClientCertificates.Add(objx509);
                    request.ProtocolVersion = HttpVersion.Version10;
                }
                else
                {
                    request = WebRequest.Create(url) as HttpWebRequest;
                }

                request.Method = "POST";//傳輸方式
                request.ContentType = "application/x-www-form-urlencoded";//協議                
                request.UserAgent = DefaultUserAgent;//請求的客戶端瀏覽器資訊,預設IE                
                request.Timeout = 6000;//超時時間，寫死6秒

                //隨同HTTP請求傳送的Cookie資訊，如果不需要身份驗證可以為空
                if (cookies != null)
                {
                    request.CookieContainer = new CookieContainer();
                    request.CookieContainer.Add(cookies);
                }

                //如果需求POST傳資料，轉換成utf-8編碼
                byte[] data = requestEncoding.GetBytes(parameters);
                request.ContentLength = data.Length;

                stream = request.GetRequestStream();
                stream.Write(data, 0, data.Length);

                stream.Close();
            }
            catch (Exception ee)
            {
                //寫日誌
                //LogHelper.
            }
            finally
            {
                if (stream != null)
                {
                    stream.Close();
                }
            }

            return request.GetResponse() as HttpWebResponse;
        }

        //驗證伺服器證書回撥自動驗證
        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
            return true; //總是接受  
        }

        /// <summary>
        /// 獲取資料
        /// </summary>
        /// <param name="HttpWebResponse">響應物件</param>
        /// <returns></returns>
        public static string OpenReadWithHttps(HttpWebResponse HttpWebResponse)
        {
            Stream responseStream = null;
            StreamReader sReader = null;
            String value = null;

            try
            {
                // 獲取響應流
                responseStream = HttpWebResponse.GetResponseStream();
                // 對接響應流(以"utf-8"字符集)
                sReader = new StreamReader(responseStream, Encoding.GetEncoding("utf-8"));
                // 開始讀取資料
                value = sReader.ReadToEnd();
            }
            catch (Exception)
            {
                //日誌異常
            }
            finally
            {
                //強制關閉
                if (sReader != null)
                {
                    sReader.Close();
                }
                if (responseStream != null)
                {
                    responseStream.Close();
                }
                if (HttpWebResponse != null)
                {
                    HttpWebResponse.Close();
                }
            }

            return value;
        }

        /// <summary>
        /// 入口方法：獲取傳回來的XML檔案
        /// </summary>
        /// <param name="url">請求的URL</param>  
        /// <param name="parameters">隨同請求POST的引數名稱及引數值字典</param>  
        /// <param name="cookies">隨同HTTP請求傳送的Cookie資訊，如果不需要身份驗證可以為空</param>  
        /// <returns></returns>
        public static string GetResultXML(string url, string parameters, CookieCollection cookies)
        {
            return OpenReadWithHttps(CreatePostHttpResponse(url, parameters, cookies));
        }

    }
}
 

/// 呼叫主程式
/// </summary>
public class Program
{
  
    static string strUrlPre = ; // 測試環境Url
    static string strKey = ;// 簽名金鑰
    static string strMethod = ;// 方法編號

    static void Main(string[] args)
    {
        //MessageBox.Show("請注意，馬上將進行儲存操作!");           

        StringBuilder sbRequestData =;//請求引數

        
        // 傳送請求
        StringBuilder sbUrl = new StringBuilder(); // 請求URL內容
        sbUrl.Append(strUrlPre);
        sbUrl.Append("?");
        sbUrl.Append("sign=" + strKeyMD5);
        sbUrl.Append("&" + sbSystemArgs.ToString());

        String strUrl = sbUrl.ToString();
        //解析xml檔案
        string resultXML = HttpWebResponseUtility.GetResultXML(sbUrl.ToString(), sbRequestData.ToString(), null);


               

    }
}