更改WebBrowser控件的用户代理

Question

我试图在Winforms应用程序中更改WebBrowser控件的UserAgent.

我已成功使用以下代码实现此目的:

[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;

public void ChangeUserAgent()
{
    List<string> userAgent = new List<string>();
    string ua = "Googlebot/2.1 (+http://www.google.com/bot.html)";

    UrlMkSetSessionOption(URLMON_OPTION_USERAGENT, ua, ua.Length, 0);
}

唯一的问题是这只能工作一次.当我尝试第二次运行ChangeUserAgent()方法时,它不起作用.它保持设置为第一个更改的值.这很烦人,我已经尝试了一切,但它不会改变不止一次.

有谁知道一种不同的,更灵活的方法？

谢谢

Answer 1

最简单的方法:

webBrowser.Navigate("http://localhost/run.php", null, null,
                    "User-Agent: Here Put The User Agent");

Answer 2

我不确定是否应该从网站上复制/粘贴,但我宁愿在这里留下答案,而不是链接.如果有人可以在评论中澄清,我将非常感激.

基本上,您必须扩展WebBrowser类.

public class ExtendedWebBrowser : WebBrowser
{
    bool renavigating = false;

    public string UserAgent { get; set; }

    public ExtendedWebBrowser()
    {
        DocumentCompleted += SetupBrowser;

        //this will cause SetupBrowser to run (we need a document object)
        Navigate("about:blank");
    }

    void SetupBrowser(object sender, WebBrowserDocumentCompletedEventArgs e)
    {
        DocumentCompleted -= SetupBrowser;
        SHDocVw.WebBrowser xBrowser = (SHDocVw.WebBrowser)ActiveXInstance;
        xBrowser.BeforeNavigate2 += BeforeNavigate;
        DocumentCompleted += PageLoaded;
    }

    void PageLoaded(object sender, WebBrowserDocumentCompletedEventArgs e)
    {

    }

    void BeforeNavigate(object pDisp, ref object url, ref object flags, ref object targetFrameName,
        ref object postData, ref object headers, ref bool cancel)
    {
        if (!string.IsNullOrEmpty(UserAgent))
        {
            if (!renavigating)
            {
                headers += string.Format("User-Agent: {0}\r\n", UserAgent);
                renavigating = true;
                cancel = true;
                Navigate((string)url, (string)targetFrameName, (byte[])postData, (string)headers);
            }
            else
            {
                renavigating = false;
            }
        }
    }
}

注意:要使用上述方法,您需要向"Microsoft Internet Controls"添加COM引用.

他也提到了你的方法,并声明WebBrowser控件似乎缓存了这个用户代理字符串,因此它不会在不重新启动进程的情况下更改用户代理.

Answer 3

此外,该功能还有一个刷新选项(根据MSDN).它对我有用(你应该在任何用户代理更改之前设置它).然后问题代码可以像这样改变:

[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;
const int URLMON_OPTION_USERAGENT_REFRESH = 0x10000002;

public void ChangeUserAgent()
{
    string ua = "Googlebot/2.1 (+http://www.google.com/bot.html)";

    UrlMkSetSessionOption(URLMON_OPTION_USERAGENT_REFRESH, null, 0, 0);
    UrlMkSetSessionOption(URLMON_OPTION_USERAGENT, ua, ua.Length, 0);
}