C#用WebBrowser与WIN API辅助模拟获取网站完整Cookie

在Winform中使用WebBrowser控件获取网站的Cookie有时候是不完整的，默认调用Document.Cookie也取不到Cookie，其中就是因为有些网站对于关键Cookie做了保护，为Cookie加上了HttpOnly的属性，HttpOnly可以防止cookie被“读取”，这时我们就需要利用WIN API用来辅助获取网站的完整Cookie了。

using System;
using System.ComponentModel;
using System.Net;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Permissions;
using System.Text;
namespace Freecms
{
    internal sealed class NativeMethods
    {
        #region enums     
        public enum ErrorFlags
        {
            ERROR_INSUFFICIENT_BUFFER = 122,
            ERROR_INVALID_PARAMETER = 87,
            ERROR_NO_MORE_ITEMS = 259
        }
        public enum InternetFlags
        {
            INTERNET_COOKIE_HTTPONLY = 8192, //Requires IE 8 or higher     
            INTERNET_COOKIE_THIRD_PARTY = 131072,
            INTERNET_FLAG_RESTRICTED_ZONE = 16
        }
        #endregion
        #region DLL Imports     
        [SuppressUnmanagedCodeSecurity, SecurityCritical, DllImport("wininet.dll", EntryPoint = "InternetGetCookieExW", CharSet = CharSet.Unicode, SetLastError = true, ExactSpelling = true)]
        internal static extern bool InternetGetCookieEx([In] string Url, [In] string cookieName, [Out] StringBuilder cookieData, [In, Out] ref uint pchCookieData, uint flags, IntPtr reserved);
        #endregion
    }
    /// <SUMMARY></SUMMARY>     
    /// 取得WebBrowser的完整Cookie。     
    /// 因为默认的webBrowser1.Document.Cookie取不到HttpOnly的Cookie     
    ///      
    public class FullWebBrowserCookie
    {
        [SecurityCritical]
        public static string GetCookieInternal(Uri uri, bool throwIfNoCookie)
        {
            uint pchCookieData = 0;
            string url = UriToString(uri);
            uint flag = (uint)NativeMethods.InternetFlags.INTERNET_COOKIE_HTTPONLY;
            //Gets the size of the string builder     
            if (NativeMethods.InternetGetCookieEx(url, null, null, ref pchCookieData, flag, IntPtr.Zero))
            {
                pchCookieData++;
                StringBuilder cookieData = new StringBuilder((int)pchCookieData);
                //Read the cookie     
                if (NativeMethods.InternetGetCookieEx(url, null, cookieData, ref pchCookieData, flag, IntPtr.Zero))
                {
                    DemandWebPermission(uri);
                    return cookieData.ToString();
                }
            }
            int lastErrorCode = Marshal.GetLastWin32Error();
            if (throwIfNoCookie || (lastErrorCode != (int)NativeMethods.ErrorFlags.ERROR_NO_MORE_ITEMS))
            {
                throw new Win32Exception(lastErrorCode);
            }
            return null;
        }
        private static void DemandWebPermission(Uri uri)
        {
            string uriString = UriToString(uri);
            if (uri.IsFile)
            {
                string localPath = uri.LocalPath;
                new FileIOPermission(FileIOPermissionAccess.Read, localPath).Demand();
            }
            else
            {
                new WebPermission(NetworkAccess.Connect, uriString).Demand();
            }
        }
        private static string UriToString(Uri uri)
        {
            if (uri == null)
            {
                throw new ArgumentNullException("uri");
            }
            UriComponents components = (uri.IsAbsoluteUri ? UriComponents.AbsoluteUri : UriComponents.SerializationInfoString);
            return new StringBuilder(uri.GetComponents(components, UriFormat.SafeUnescaped), 2083).ToString();
        }
    }
}

调用方法(webBrowser1.Url为webBrowser1控件登陆后包含cookie信息的Url)：

string pCookie=Freecms.FullWebBrowserCookie.GetCookieInternal(webBrowser1.Url, false);