在C#用HttpWebRequest中发送GET/HTTP/HTTPS请求

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Net;
using System.Text;
using System.IO;
using System.Security.Cryptography.X509Certificates;
using System.Net.Security;

namespace SD2.StockShare
{
    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)";

        /// <summary> 
        /// 创建GET方式的HTTP请求 
        /// </summary>
        /// <param name="url">请求的URL</param>
        /// 
        /// <param name="timeout">请求的超时时间</param> 
        /// <param name="userAgent">请求的客户端浏览器信息，可以为空</param> 
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</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> 
        /// 创建POST方式的HTTP请求 
        /// </summary>  
        /// <param name="url">请求的URL</param>      
        /// <param name="parameters">随同请求POST的参数名称及参数值字典</param>  
        /// <param name="timeout">请求的超时时间</param>  
        /// <param name="userAgent">请求的客户端浏览器信息，可以为空</param> 
        /// <param name="requestEncoding">发送HTTP请求时所用的编码</param> 
        /// <param name="cookies">随同HTTP请求发送的Cookie信息，如果不需要身份验证可以为空</param> 
        /// <returns></returns> 
        public static HttpWebResponse CreatePostHttpResponse(string url, IDictionary<string, string> parameters, int? timeout, string userAgent, Encoding requestEncoding, CookieCollection cookies)
        {

            if (string.IsNullOrEmpty(url))
            {
                throw new ArgumentNullException("url");
            }
            if (requestEncoding == null)
            {
                throw new ArgumentNullException("requestEncoding");
            }
            HttpWebRequest request = null;
            //如果是发送HTTPS请求 
            if (url.StartsWith("https", StringComparison.OrdinalIgnoreCase))
            {
                ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(CheckValidationResult);
                request = WebRequest.Create(url) as HttpWebRequest;
                request.ProtocolVersion = HttpVersion.Version10;
            }
            else
            {
                request = WebRequest.Create(url) as HttpWebRequest;
            }
            request.Method = "POST";
            request.ContentType = "application/x-www-form-urlencoded";
            if (!string.IsNullOrEmpty(userAgent))
            {
                request.UserAgent = userAgent;
            }
            else
            {
                request.UserAgent = DefaultUserAgent;
            }
            if (timeout.HasValue)
            {
                request.Timeout = timeout.Value;
            }
            if (cookies != null)
            {
                request.CookieContainer = new CookieContainer();
                request.CookieContainer.Add(cookies);
            }
            //如果需要POST数据 
            if (!(parameters == null || parameters.Count == 0))
            {
                StringBuilder buffer = new StringBuilder();
                int i = 0;
                foreach (string key in parameters.Keys)
                {
                    if (i > 0)
                    {
                        buffer.AppendFormat("&{0}={1}", key, parameters[key]);
                    }
                    else
                    {
                        buffer.AppendFormat("{0}={1}", key, parameters[key]);
                    }
                    i++;
                }
                byte[] data = requestEncoding.GetBytes(buffer.ToString());
                using (Stream stream = request.GetRequestStream())
                {
                    stream.Write(data, 0, data.Length);
                }
            }
            return request.GetResponse() as HttpWebResponse;
        }
        private static bool CheckValidationResult(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors errors)
        {
            return true; //总是接受
        }
    }
}

　　

用法举例 这个类用起来也很简单： （1）POST数据到HTTPS站点，用它来登录百度：

string loginUrl = "https://passport.baidu.com/?login"; 

string userName = "userName"; 

string password = "password"; 

string tagUrl = "http://cang.baidu.com/"+userName+"/tags"; 

Encoding encoding = Encoding.GetEncoding("gb2312"); 

IDictionary<string, string> parameters = new Dictionary<string, string>(); 

parameters.Add("tpl", "fa"); 

parameters.Add("tpl_reg", "fa"); 

parameters.Add("u", tagUrl); 

parameters.Add("psp_tt", "0"); 

parameters.Add("username", userName); 

parameters.Add("password", password); 

parameters.Add("mem_pass", "1"); 

HttpWebResponse response = HttpWebResponseUtility.CreatePostHttpResponse(loginUrl, parameters, null, null, encoding, null); 

string cookieString = response.Headers["Set-Cookie"];

（2）发送GET请求到HTTP站点 在cookieString中包含了服务器端返回的会话信息数据，从中提取了之后可以设置Cookie下次登录时带上这个Cookie就可以以认证用户的信息，假设我们已经登录成功并且获取了Cookie，那么发送GET请求的代码如下：

string userName = "userName"; 

string tagUrl = "http://cang.baidu.com/"+userName+"/tags"; 

CookieCollection cookies = new CookieCollection();//如何从response.Headers["Set-Cookie"];中获取并设置CookieCollection的代码略

response = HttpWebResponseUtility.CreateGetHttpResponse(tagUrl, null, null, cookies); 

(3)发送POST请求到HTTP站点 以登录51CTO为例：

string loginUrl = "http://home.51cto.com/index.php?s=/Index/doLogin"; 

string userName = "userName"; 

string password = "password"; 

IDictionary<string, string> parameters = new Dictionary<string, string>(); 

parameters.Add("email", userName); 

parameters.Add("passwd", password); 

HttpWebResponse response = HttpWebResponseUtility.CreatePostHttpResponse(loginUrl, parameters, null, null, Encoding.UTF8, null); 

在这里说句题外话，CSDN的登录处理是由http://passport.csdn.net/ajax/accounthandler.ashx这个Handler来处理的。

 转自：http://zhoufoxcn.blog.51cto.com/792419/561934

　　下载：https://files.cnblogs.com/xffy1028/HttpWebResponseUtility.rar