通过特定的网络适配器发送HttpWebRequest

时间:2011-05-02 18:28:50

标签: c# httpwebrequest

我的计算机连接了两个无线网络适配器,每个都连接到不同的网络。我想构建一种我的浏览器将连接到的代理服务器,它将从不同的适配器发送每个HTTP请求,因此网页上的加载时间会更短。 你们知道我怎么决定从哪个网络适配器发送HttpWebRequest?

谢谢:)

更新

我使用了这段代码:

public static IPEndPoint BindIPEndPointCallback(ServicePoint servicePoint, IPEndPoint remoteEndPoint, int retryCount)
{
    List<IPEndPoint> ipep = new List<IPEndPoint>();
    foreach (var i in System.Net.NetworkInformation.NetworkInterface.GetAllNetworkInterfaces())
    {
        foreach (var ua in i.GetIPProperties().UnicastAddresses)
            ipep.Add(new IPEndPoint(ua.Address, 0));
    }
    return new IPEndPoint(ipep[1].Address, ipep[1].Port);
}

private void button1_Click(object sender, EventArgs e)
{
    HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://whatismyip.com");
    request.ServicePoint.BindIPEndPointDelegate = new BindIPEndPoint(BindIPEndPointCallback);
    HttpWebResponse response = (HttpWebResponse)request.GetResponse();
    StreamReader sr = new StreamReader(response.GetResponseStream());
    string x = sr.ReadToEnd();
}

但即使改变IPEndPoint,我发送的是从WhatIsMyIp获得的IP仍然是相同的......任何帮助?

3 个答案:

答案 0 :(得分:6)

BindIPEndPointDelegate可能就是你在这里所追求的。它允许您强制将特定的本地IP作为发送HttpWebRequest的终点。

答案 1 :(得分:2)

此示例适用于我:

using System;
using System.Net;

class Program
{
    public static void Main ()
    {
        foreach (var ip in Dns.GetHostAddresses (Dns.GetHostName ())) 
        {
            Console.WriteLine ("Request from: " + ip);
            var request = (HttpWebRequest)HttpWebRequest.Create ("http://ns1.vianett.no/");
            request.ServicePoint.BindIPEndPointDelegate = delegate {
                return new IPEndPoint (ip, 0);
            };
            var response = (HttpWebResponse)request.GetResponse ();
            Console.WriteLine ("Actual IP: " + response.GetResponseHeader ("X-YourIP"));
            response.Close ();
        }
    }
}

答案 2 :(得分:0)

这是因为WebRequest使用ServicePointManager并且它缓存用于单个URI的实际ServicePoint。所以在你的情况下,BindIPEndPointDelegate只调用一次,所有后续CreateRequest重用相同的绑定接口。以下是TcpClient实际工作的更低级别示例:

        foreach (var iface in NetworkInterface.GetAllNetworkInterfaces())
        {
            if (iface.OperationalStatus == OperationalStatus.Up && iface.NetworkInterfaceType != NetworkInterfaceType.Loopback)
            {
                Console.WriteLine("Interface: {0}\t{1}\t{2}", iface.Name, iface.NetworkInterfaceType, iface.OperationalStatus);
                foreach (var ua in iface.GetIPProperties().UnicastAddresses)
                {
                    Console.WriteLine("Address: " + ua.Address);
                    try
                    {
                        using (var client = new TcpClient(new IPEndPoint(ua.Address, 0)))
                        {
                            client.Connect("ns1.vianett.no", 80);
                            var buf = Encoding.UTF8.GetBytes("GET / HTTP/1.1\r\nConnection: close\r\nHost: ns1.vianett.no\r\n\r\n");
                            client.GetStream().Write(buf, 0, buf.Length);
                            var sr = new StreamReader(client.GetStream());
                            var all = sr.ReadToEnd();
                            var match = Regex.Match(all, "(?mi)^X-YourIP: (?'a'.+)$");
                            Console.WriteLine("Your address is " + (match.Success ? match.Groups["a"].Value : all));
                        }
                    }
                    catch (Exception ex)
                    {
                        Console.WriteLine(ex.Message);
                    }
                }
            }
        }