Winform中修改WebBrowser控件User-Agent的方法

最新推荐文章于 2021-04-23 14:20:59 发布

转载最新推荐文章于 2021-04-23 14:20:59 发布 · 2.2k 阅读

本文介绍了一个简单的C#代码片段，用于在默认的UserAgent字符串后面追加额外的字符串。该方法通过调用Win32 API的UrlMkSetSessionOption函数来修改UserAgent字符串，从而影响浏览器发送的HTTP头部信息。

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Reflection;

namespace WindowsFormsApplication2
{
public class UserAgentHelper
{
private static string defaultUserAgent = null;

[DllImport("urlmon.dll", CharSet = CharSet.Ansi)]
private static extern int UrlMkSetSessionOption(int dwOption, string pBuffer, int dwBufferLength, int dwReserved);

const int URLMON_OPTION_USERAGENT = 0x10000001;

    /// <summary>
    /// 在默认的UserAgent后面加一部分
    /// </summary>
    public static void AppendUserAgent(string appendUserAgent)
    {
      if (string.IsNullOrEmpty(defaultUserAgent))
        defaultUserAgent = GetDefaultUserAgent();

      string ua = defaultUserAgent + ";" + appendUserAgent;
      ChangeUserAgent(ua);
    }

    /// <summary>
    /// 修改UserAgent
    /// </summary>
    public static void ChangeUserAgent(string userAgent)
    {
      UrlMkSetSessionOption(URLMON_OPTION_USERAGENT, userAgent, userAgent.Length, 0);
    }

    /// <summary>
    /// 一个很BT的获取IE默认UserAgent的方法
    /// </summary>
    private static string GetDefaultUserAgent()
    {
      WebBrowser wb = new WebBrowser();
      wb.Navigate("about:blank");
      while (wb.IsBusy) Application.DoEvents();
      object window = wb.Document.Window.DomWindow;
      Type wt = window.GetType();
      object navigator = wt.InvokeMember("navigator", BindingFlags.GetProperty,
          null, window, new object[] { });
      Type nt = navigator.GetType();
      object userAgent = nt.InvokeMember("userAgent", BindingFlags.GetProperty,
          null, navigator, new object[] { });
      return userAgent.ToString();
    }
}
}