C# 从 Internet Explorer 获取代理设置

Question

我在德国的某家公司遇到了问题。他们在他们的网络中使用代理，我的程序无法与服务器通信。

IE 使用此设置:

意思是: 自动检测设置

这是代码:

public static bool CompleteValidation(string regKey)
{
    string uri = "***";

    int c = 1;
    if (Counter < 5) c = 6 - Counter;
    string response = "";
    try
    {
        System.Net.ServicePointManager.Expect100Continue = false;
        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(uri);
        request.AllowWriteStreamBuffering = true;
        request.Method = "POST";
        request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0) Gecko/20100101 Firefox/5.0";
        request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
        request.Headers.Add(HttpRequestHeader.AcceptLanguage, "pl,en-us;q=0.7,en;q=0.3");
        request.Headers.Add(HttpRequestHeader.AcceptEncoding, "gzip, deflate");
        request.Headers.Add(HttpRequestHeader.AcceptCharset, "ISO-8859-2,utf-8;q=0.7,*;q=0.7");
        request.KeepAlive = true;

        //proxy settings
        string exepath = Path.GetDirectoryName(Application.ExecutablePath);
        string proxySettings = exepath + @"\proxy.ini";
        WebProxy wp = new WebProxy();
        if (File.Exists(proxySettings)) {
            request.Proxy = WebRequest.DefaultWebProxy;
            IniFile ini = new IniFile(proxySettings);
            string user = ini.IniReadValue("Proxy", "User");
            string pass = ini.IniReadValue("Proxy", "Password");
            string domain = ini.IniReadValue("Proxy", "Domain");
            string ip = ini.IniReadValue("Proxy", "IP");
            string port_s = ini.IniReadValue("Proxy", "Port");
            int port = 0;
            if (!string.IsNullOrEmpty(ip))
            {
                if (!string.IsNullOrEmpty(port_s))
                {
                    try
                    {
                        port = Convert.ToInt32(port_s);
                    }
                    catch (Exception e)
                    {
                        ErrorLog.AddToLog("Problem with conversion of port:");
                        ErrorLog.AddToLog(e.Message);
                        ErrorLog.ShowLogWindow();
                    }
                    wp = new WebProxy(ip, port);
                } else {
                    wp = new WebProxy(ip);
                }

            }
            if (string.IsNullOrEmpty(domain))
                wp.Credentials = new NetworkCredential(user, pass);
            else
                wp.Credentials = new NetworkCredential(user, pass, domain);
            request.Proxy = wp;
        }

        string post = "***";
        request.ContentLength = post.Length;
        request.ContentType = "application/x-www-form-urlencoded";
        StreamWriter writer = null;
        try
        {
            writer = new StreamWriter(request.GetRequestStream()); // Here is the WebException thrown
            writer.Write(post);
            writer.Close();
        }
        catch (Exception e)
        {
            ErrorLog.AddToLog("Problem with request sending:");
            ErrorLog.AddToLog(e.Message);
            ErrorLog.ShowLogWindow();
        }
        HttpWebResponse Response = null;
        try 
        {
           Response  = (HttpWebResponse)request.GetResponse();
        }
        catch (Exception e)
        {
            ErrorLog.AddToLog("Problem with response:");
            ErrorLog.AddToLog(e.Message);
            ErrorLog.ShowLogWindow();
        }

        //Request.Proxy = WebProxy.GetDefaultProxy();
        //Request.Proxy.Credentials = CredentialCache.DefaultCredentials;
        string sResponseHeader = Response.ContentEncoding; // get response header

        if (!string.IsNullOrEmpty(sResponseHeader))
        {
            if (sResponseHeader.ToLower().Contains("gzip"))
            {
                byte[] b = DecompressGzip(Response.GetResponseStream());
                response = System.Text.Encoding.GetEncoding(Response.ContentEncoding).GetString(b);
            }
            else if (sResponseHeader.ToLower().Contains("deflate"))
            {
                byte[] b = DecompressDeflate(Response.GetResponseStream());
                response = System.Text.Encoding.GetEncoding(Response.ContentEncoding).GetString(b);
            }
        }
        // uncompressed, standard response
        else
        {
            StreamReader ResponseReader = new StreamReader(Response.GetResponseStream());
            response = ResponseReader.ReadToEnd();
            ResponseReader.Close();
        }
    }
    catch (Exception e)
    {
        ErrorLog.AddToLog("Problem with comunication:");
        ErrorLog.AddToLog(e.Message);
        ErrorLog.ShowLogWindow();
    }

    if (response == "***")
    {
        SaveKeyFiles();
        WriteRegKey(regKey);
        RenewCounter();
        return true;
    }
    else
    {
        return false;
    }

}

我的程序将其记录为:

[09:13:18] Searching for hardware ID
[09:13:56] Problem with response:
[09:13:56] The remote server returned an error: (407) Proxy Authentication Required.
[09:15:04] problem with comunication:
[09:15:04] Object reference not set to an object instance.

如果他们写入用户并传递到 proxy.ini 文件中，程序就可以运行。但问题是他们做不到。不知何故，IE 可以在没有它的情况下工作。有没有办法从 IE 或系统中获取这些设置？

Answer 1

使用GetSystemWebProxy返回系统默认代理是什么。

    WebRequest.DefaultProxy = WebRequest.GetSystemWebProxy();

但是每个HttpWebRequest默认情况下应自动填写此信息。例如，独立控制台应用程序中的以下代码片段应该在配置了 PAC 文件的系统上打印正确的信息。

    HttpWebRequest myWebRequest=(HttpWebRequest)WebRequest.Create("http://www.microsoft.com");

    // Obtain the 'Proxy' of the  Default browser.  
    IWebProxy proxy = myWebRequest.Proxy;
    // Print the Proxy Url to the console.
    if (proxy != null)
    {
        Console.WriteLine("Proxy: {0}", proxy.GetProxy(myWebRequest.RequestUri));
    } 
    else
    {
        Console.WriteLine("Proxy is null; no proxy will be used");
    }