在做数据采集时，有些网站需要输入验证码，但各网站验证码都不同，不可能有完美的识别验证码的代码，所以我也没去研究，我所采取的方案是：在winform里通过WebBrowser调用网页先手动登录系统，然后再通过webBrowser1.Document.Cookie获取其Cookie，再将其用到HttpWebRequest里用来访问自己需要的页。

一直用的都没有问题，但最近在对一个网站操作时总是不能获取完整Cookie，百思不得其解，使用Fiddler2对比发现，不能获取到的Cookie里最后有一个HttpOnly的标识，顺藤摸瓜发现原来webBrowser1.Document.Cookie里是取不到HttpOnly的Cookie的，也找到解决方法：

1 using System;     2 using System.ComponentModel;     3 using System.Net;     4 using System.Runtime.InteropServices;     5 using System.Security;     6 using System.Security.Permissions;     7 using System.Text;     8     9    10 internal sealed class NativeMethods    11 {   12     #region enums    13    14     public enum ErrorFlags    15     {    16         ERROR_INSUFFICIENT_BUFFER = 122,    17         ERROR_INVALID_PARAMETER = 87,    18         ERROR_NO_MORE_ITEMS = 259    19     }    20    21     public enum InternetFlags    22     {    23         INTERNET_COOKIE_HTTPONLY = 8192, //Requires IE 8 or higher    24         INTERNET_COOKIE_THIRD_PARTY = 131072,    25         INTERNET_FLAG_RESTRICTED_ZONE = 16    26     }   27   28     #endregion   29   30     #region DLL Imports    31    32     [SuppressUnmanagedCodeSecurity, SecurityCritical, DllImport("wininet.dll", EntryPoint = "InternetGetCookieExW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]    33     internal static extern bool InternetGetCookieEx([In] string Url, [In] string cookieName, [Out] StringBuilder cookieData, [In, Out] ref uint pchCookieData, uint flags, IntPtr reserved);   34   35     #endregion    36 }    37    38    39 /// 
    40 /// 取得WebBrowser的完整Cookie。    41 /// 因为默认的webBrowser1.Document.Cookie取不到HttpOnly的Cookie    42 ///     43 public class FullWebBrowserCookie    44 {    45    46     [SecurityCritical]    47     public static string GetCookieInternal(Uri uri, bool throwIfNoCookie)    48     {    49         uint pchCookieData = 0;    50         string url = UriToString(uri);    51         uint flag = (uint)NativeMethods.InternetFlags.INTERNET_COOKIE_HTTPONLY;    52    53         //Gets the size of the string builder    54         if (NativeMethods.InternetGetCookieEx(url, null, null, ref pchCookieData, flag, IntPtr.Zero))    55         {    56             pchCookieData++;    57             StringBuilder cookieData = new StringBuilder((int)pchCookieData);    58    59             //Read the cookie    60             if (NativeMethods.InternetGetCookieEx(url, null, cookieData, ref pchCookieData, flag, IntPtr.Zero))    61             {    62                 DemandWebPermission(uri);    63                 return cookieData.ToString();    64             }    65         }    66    67         int lastErrorCode = Marshal.GetLastWin32Error();    68    69         if (throwIfNoCookie || (lastErrorCode != (int)NativeMethods.ErrorFlags.ERROR_NO_MORE_ITEMS))    70         {    71             throw new Win32Exception(lastErrorCode);    72         }    73    74         return null;    75     }    76    77     private static void DemandWebPermission(Uri uri)    78     {    79         string uriString = UriToString(uri);    80    81         if (uri.IsFile)    82         {    83             string localPath = uri.LocalPath;    84             new FileIOPermission(FileIOPermissionAccess.Read, localPath).Demand();    85         }    86         else   87         {    88             new WebPermission(NetworkAccess.Connect, uriString).Demand();    89         }    90     }    91    92     private static string UriToString(Uri uri)    93     {    94         if (uri == null)    95         {    96             throw new ArgumentNullException("uri");    97         }    98    99         UriComponents components = (uri.IsAbsoluteUri ? UriComponents.AbsoluteUri : UriComponents.SerializationInfoString);   100         return new StringBuilder(uri.GetComponents(components, UriFormat.SafeUnescaped), 2083).ToString();   101     }   102 }