這個需求來自于我最近練手的一個項目，在項目中我需要將一些自己發表的和收藏整理的網文集中到一個地方存放，如果全部采用手工操作工作量大而且繁瑣，因此周公決定利用C#來實現。在很多地方都需要驗證用戶身份才可以進行下一步操作，這就免不了POST請求來登錄，在實際過程中發現有些網站登錄是HTTPS形式的，在解決過程中遇到了一些小問題，現在跟大家分享。
通用輔助類
下面是我編寫的一個輔助類，在這個類中采用了HttpWebRequest中發送GET/HTTP/HTTPS請求，因為有的時候需要獲取認證信息（如Cookie），所以返回的是HttpWebResponse對象，有了返回的HttpWebResponse實例，可以獲取登錄過程中返回的會話信息，也可以獲取響應流。
代碼如下：
using System;
using System.Collections.Generic;
using System.Linq; using System.Text; using System.Net.Security; using System.Security.Cryptography.X509Certificates; using System.DirectoryServices.Protocols; using System.ServiceModel.Security; using System.Net; using System.IO; using System.IO.Compression; using System.Text.RegularExpressions; namespace BaiduCang { /// <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)"; /// <summary> /// 創建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信息，可以為空</param> /// <param name="cookies">隨同HTTP請求發送的Cookie信息，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> /// 創建POST方式的HTTP請求 /// </summary> /// <param name="url">請求的URL</param> /// <param name="parameters">隨同請求POST的參數名稱及參數值字典</param> /// <param name="timeout">請求的超時時間</param> /// <param name="userAgent">請求的客戶端瀏覽器信息，可以為空</param> /// <param name="requestEncoding">發送HTTP請求時所用的編碼</param> /// <param name="cookies">隨同HTTP請求發送的Cookie信息，如果不需要身份驗證可以為空</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; //如果是發送HTTPS請求 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數據 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(