我正在运行一个服务器,我想显示我自己的IP地址。

获取计算机自身(如果可能的话,外部)IP地址的语法是什么?

有人编写了以下代码。

IPHostEntry host;
string localIP = "?";
host = Dns.GetHostEntry(Dns.GetHostName());
foreach (IPAddress ip in host.AddressList)
{
    if (ip.AddressFamily.ToString() == "InterNetwork")
    {
        localIP = ip.ToString();
    }
}
return localIP;

然而,我通常不信任作者,我不理解这段代码。有更好的方法吗?


不,这几乎是最好的方法。由于一台机器可能有多个IP地址,您需要迭代它们的集合以找到合适的一个。

编辑:我唯一想改变的是改变这个:

if (ip.AddressFamily.ToString() == "InterNetwork")

:

if (ip.AddressFamily == AddressFamily.InterNetwork)

不需要ToString一个枚举进行比较。


namespace NKUtilities 
{
    using System;
    using System.Net;
    using System.Net.Sockets;

    public class DNSUtility
    {
        public static int Main(string [] args)
        {
            string strHostName = "";
            try {

                if(args.Length == 0)
                {
                    // Getting Ip address of local machine...
                    // First get the host name of local machine.
                    strHostName = Dns.GetHostName();
                    Console.WriteLine ("Local Machine's Host Name: " +  strHostName);
                }
                else
                {
                    // Otherwise, get the IP address of the host provided on the command line.
                    strHostName = args[0];
                }

                // Then using host name, get the IP address list..
                IPHostEntry ipEntry = Dns.GetHostEntry (strHostName);
                IPAddress [] addr = ipEntry.AddressList;

                for(int i = 0; i < addr.Length; i++)
                {
                    Console.WriteLine("IP Address {0}: {1} ", i, addr[i].ToString());
                }
                return 0;

            } 
            catch(SocketException se) 
            {
                Console.WriteLine("{0} ({1})", se.Message, strHostName);
                return -1;
            } 
            catch(Exception ex) 
            {
                Console.WriteLine("Error: {0}.", ex.Message);
                return -1;
            }
        }
    }
}

详情请看这里。

你必须记住你的电脑可以有多个IP(实际上它总是这样)-所以你是哪一个。


using System.Net;

string host = Dns.GetHostName();
IPHostEntry ip = Dns.GetHostEntry(host);
Console.WriteLine(ip.AddressList[0].ToString());

刚在我的机器上测试过了,还能用。


也许通过外部IP,您可以考虑(如果您在Web服务器上下文中)使用此方法

Request.ServerVariables["LOCAL_ADDR"];

我也在问你同样的问题,我在这篇stackoverflow的文章中找到了它。

这对我很管用。


了解你的公共IP的唯一方法是让别人告诉你;这段代码可以帮助你:

public string GetPublicIP()
{
    String direction = "";
    WebRequest request = WebRequest.Create("http://checkip.dyndns.org/");
    using (WebResponse response = request.GetResponse())
    using (StreamReader stream = new StreamReader(response.GetResponseStream()))
    {
        direction = stream.ReadToEnd();
    }

    //Search for the ip in the html
    int first = direction.IndexOf("Address: ") + 9;
    int last = direction.LastIndexOf("</body>");
    direction = direction.Substring(first, last - first);

    return direction;
}

WebClient webClient = new WebClient();
string IP = webClient.DownloadString("http://myip.ozymo.com/");

试试这个:

 IPAddress[] localIPs = Dns.GetHostAddresses(Dns.GetHostName());
 String MyIp = localIPs[0].ToString();

清洁和一体解决方案:D

//This returns the first IP4 address or null
return Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork);

为了获取当前的公网IP地址,你所需要做的就是在页面加载事件中创建一个ASPX页面,代码如下:

Response.Write(HttpContext.Current.Request.UserHostAddress.ToString());

如果你不能依赖于从DNS服务器获取你的IP地址(这发生在我身上),你可以使用以下方法:

System.Net.NetworkInformation命名空间包含一个NetworkInterface类,该类有一个静态的GetAllNetworkInterfaces方法。

此方法将返回您机器上的所有“网络接口”,而且通常有相当多的“网络接口”,即使您的机器上只安装了无线适配器和/或以太网适配器硬件。所有这些网络接口都有本地计算机的有效IP地址,尽管您可能只需要一个。

如果您正在寻找一个IP地址,那么您将需要筛选列表,直到您可以识别正确的地址。你可能需要做一些实验,但我成功地采用了以下方法:

通过检查OperationalStatus == OperationalStatus. up过滤掉任何非活动的网络接口。这将排除您的物理以太网适配器,例如,如果您没有插入网线。

对于每个NetworkInterface,你可以使用GetIPProperties方法获得一个IPInterfaceProperties对象,并且从一个IPInterfaceProperties对象中,你可以访问UnicastIPAddressInformation对象列表的UnicastAddresses属性。

通过检查DuplicateAddressDetectionState == DuplicateAddressDetectionState过滤掉非首选单播地址。首选 通过检查AddressPreferredLifetime != UInt32.MaxValue过滤出“虚拟”地址。

此时,我取与所有这些过滤器匹配的第一个单播地址(如果有的话)的地址。

编辑:

[2018年5月16日修订的代码,以包括上述文本中提到的重复地址检测状态和首选生存期的条件]

下面的示例演示了基于操作状态、地址族、排除环回地址(127.0.0.1)、重复地址检测状态和首选生存期的过滤。

static IEnumerable<IPAddress> GetLocalIpAddresses()
{
    // Get the list of network interfaces for the local computer.
    var adapters = NetworkInterface.GetAllNetworkInterfaces();

    // Return the list of local IPv4 addresses excluding the local
    // host, disconnected, and virtual addresses.
    return (from adapter in adapters
            let properties = adapter.GetIPProperties()
            from address in properties.UnicastAddresses
            where adapter.OperationalStatus == OperationalStatus.Up &&
                  address.Address.AddressFamily == AddressFamily.InterNetwork &&
                  !address.Equals(IPAddress.Loopback) &&
                  address.DuplicateAddressDetectionState == DuplicateAddressDetectionState.Preferred &&
                  address.AddressPreferredLifetime != UInt32.MaxValue
            select address.Address);
}

这是在VB中获取所有本地ip的csv格式。网

Imports System.Net
Imports System.Net.Sockets

Function GetIPAddress() As String
    Dim ipList As List(Of String) = New List(Of String)
    Dim host As IPHostEntry
    Dim localIP As String = "?"
    host = Dns.GetHostEntry(Dns.GetHostName())
    For Each ip As IPAddress In host.AddressList
        If ip.AddressFamily = AddressFamily.InterNetwork Then
            localIP = ip.ToString()
            ipList.Add(localIP)
        End If
    Next
    Dim ret As String = String.Join(",", ipList.ToArray)
    Return ret
End Function

namespace NKUtilities 
{
    using System;
    using System.Net;

    public class DNSUtility
    {
        public static int Main (string [] args)
        {

          String strHostName = new String ("");
          if (args.Length == 0)
          {
              // Getting Ip address of local machine...
              // First get the host name of local machine.
              strHostName = Dns.GetHostName ();
              Console.WriteLine ("Local Machine's Host Name: " +  strHostName);
          }
          else
          {
              strHostName = args[0];
          }

          // Then using host name, get the IP address list..
          IPHostEntry ipEntry = DNS.GetHostByName (strHostName);
          IPAddress [] addr = ipEntry.AddressList;

          for (int i = 0; i < addr.Length; i++)
          {
              Console.WriteLine ("IP Address {0}: {1} ", i, addr[i].ToString ());
          }
          return 0;
        }    
     }
}

不要一直依赖互联网,因为你可以有多个设备也使用IP4,这会破坏获取IP的结果。 现在,如果你愿意,你可以复制这个,并请检查它或更新它以你认为合适的方式。

首先我得到路由器(网关)的地址 如果它回来,我连接到一个网关(这意味着没有直接连接到调制解调器无线与否),然后我们有我们的网关地址作为IPAddress,否则我们一个空指针IPAddress引用。

Then we need to get the computer's list of IPAddresses. This is where things are not that hard because routers (all routers) use 4 bytes (...). The first three are the most important because any computer connected to it will have the IP4 address matching the first three bytes. Ex: 192.168.0.1 is standard for router default IP unless changed by the adminstrator of it. '192.168.0' or whatever they may be is what we need to match up. And that is all I did in IsAddressOfGateway function. The reason for the length matching is because not all addresses (which are for the computer only) have the length of 4 bytes. If you type in netstat in the cmd, you will find this to be true. So there you have it. Yes, it takes a little more work to really get what you are looking for. Process of elimination. And for God's sake, do not find the address by pinging it which takes time because first you are sending the address to be pinged and then it has to send the result back. No, work directly with .Net classes which deal with your system environment and you will get the answers you are looking for when it has to solely do with your computer.

Now if you are directly connected to your modem, the process is almost the same because the modem is your gateway but the submask is not the same because your getting the information directly from your DNS Server via modem and not masked by the router serving up the Internet to you although you still can use the same code because the last byte of the IP assigned to the modem is 1. So if IP sent from the modem which does change is 111.111.111.1' then you will get 111.111.111.(some byte value). Keep in mind the we need to find the gateway information because there are more devices which deal with internet connectivity than your router and modem.

Now you see why you DON'T change your router's first two bytes 192 and 168. These are strictly distinguished for routers only and not internet use or we would have a serious issue with IP Protocol and double pinging resulting in crashing your computer. Image that your assigned router IP is 192.168.44.103 and you click on a site with that IP as well. OMG! Your computer would not know what to ping. Crash right there. To avoid this issue, only routers are assigned these and not for internet usage. So leave the first two bytes of the router alone.

static IPAddress FindLanAddress()
{
    IPAddress gateway = FindGetGatewayAddress();
    if (gateway == null)
        return null;

    IPAddress[] pIPAddress = Dns.GetHostAddresses(Dns.GetHostName());

    foreach (IPAddress address in pIPAddress)            {
        if (IsAddressOfGateway(address, gateway))
                return address;
    return null;
}
static bool IsAddressOfGateway(IPAddress address, IPAddress gateway)
{
    if (address != null && gateway != null)
        return IsAddressOfGateway(address.GetAddressBytes(),gateway.GetAddressBytes());
    return false;
}
static bool IsAddressOfGateway(byte[] address, byte[] gateway)
{
    if (address != null && gateway != null)
    {
        int gwLen = gateway.Length;
        if (gwLen > 0)
        {
            if (address.Length == gateway.Length)
            {
                --gwLen;
                int counter = 0;
                for (int i = 0; i < gwLen; i++)
                {
                    if (address[i] == gateway[i])
                        ++counter;
                }
                return (counter == gwLen);
            }
        }
    }
    return false;

}
static IPAddress FindGetGatewayAddress()
{
    IPGlobalProperties ipGlobProps = IPGlobalProperties.GetIPGlobalProperties();

    foreach (NetworkInterface ni in NetworkInterface.GetAllNetworkInterfaces())
    {
        IPInterfaceProperties ipInfProps = ni.GetIPProperties();
        foreach (GatewayIPAddressInformation gi in ipInfProps.GatewayAddresses)
            return gi.Address;
    }
    return null;
}

using System;
using System.Net;

namespace IPADDRESS
{
    class Program
    {
        static void Main(string[] args)
        {
            String strHostName = string.Empty;
            if (args.Length == 0)
            {                
                /* First get the host name of local machine.*/
                strHostName = Dns.GetHostName();
                Console.WriteLine("Local Machine's Host Name: " + strHostName);
            }
            else
            {
                strHostName = args[0];
            }
            /* Then using host name, get the IP address list..*/
            IPHostEntry ipEntry = Dns.GetHostByName(strHostName);
            IPAddress[] addr = ipEntry.AddressList;
            for (int i = 0; i < addr.Length; i++)
            {
                Console.WriteLine("IP Address {0}: {1} ", i, addr[i].ToString());
            }
            Console.ReadLine();
        }
    }
}

return Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork);

简单的一行代码,返回第一个内部IPV4地址,如果没有则返回null。作为上面的注释添加,但可能对某人有用(上面的一些解决方案将返回多个需要进一步过滤的地址)。

它也很容易返回环回而不是null,我猜用:

return Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork) ?? new IPAddress( new byte[] {127, 0, 0, 1} );

为了找到IP地址列表,我已经使用了这个解决方案

public static IEnumerable<string> GetAddresses()
{
    var host = Dns.GetHostEntry(Dns.GetHostName());
    return (from ip in host.AddressList where ip.AddressFamily == AddressFamily.lo select ip.ToString()).ToList();
}

但我个人喜欢下面的解决方案,以获得本地有效的IP地址

public static IPAddress GetIPAddress(string hostName)
{
    Ping ping = new Ping();
    var replay = ping.Send(hostName);

    if (replay.Status == IPStatus.Success)
    {
        return replay.Address;
    }
    return null;
 }

public static void Main()
{
    Console.WriteLine("Local IP Address: " + GetIPAddress(Dns.GetHostName()));
    Console.WriteLine("Google IP:" + GetIPAddress("google.com");
    Console.ReadLine();
}

LINQ解决方案:

Dns.GetHostEntry(Dns.GetHostName()).AddressList.Where(ip => ip.AddressFamily == AddressFamily.InterNetwork).Select(ip => ip.ToString()).FirstOrDefault() ?? ""

我只是想添加我自己的一行代码(尽管已经有许多其他有用的答案)。


string ipAddress = new WebClient().DownloadString("http://icanhazip.com");


如果你想避免使用DNS:

List<IPAddress> ipList = new List<IPAddress>();
foreach (var netInterface in NetworkInterface.GetAllNetworkInterfaces())
{
    foreach (var address in netInterface.GetIPProperties().UnicastAddresses)
    {
        if (address.Address.AddressFamily == AddressFamily.InterNetwork)
        {
            Console.WriteLine("found IP " + address.Address.ToString());
            ipList.Add(address.Address);
        }
    }
}

这是我解决它的方法。我知道如果你有几个物理接口,这可能不会选择你想要的确切的eth。

private string FetchIP()
{
    //Get all IP registered
    List<string> IPList = new List<string>();
    IPHostEntry host;
    host = Dns.GetHostEntry(Dns.GetHostName());
    foreach (IPAddress ip in host.AddressList)
    {
        if (ip.AddressFamily == AddressFamily.InterNetwork)
        {
            IPList.Add(ip.ToString());
        }
    }

    //Find the first IP which is not only local
    foreach (string a in IPList)
    {
        Ping p = new Ping();
        string[] b = a.Split('.');
        string ip2 = b[0] + "." + b[1] + "." + b[2] + ".1";
        PingReply t = p.Send(ip2);
        p.Dispose();
        if (t.Status == IPStatus.Success && ip2 != a)
        {
            return a;
        }
    }
    return null;
}

如果你在内部网络中运行,你将能够获得本地机器的IP地址,如果不是,你将获得外部IP地址: 网络:

//this will bring the IP for the current machine on browser
System.Web.HttpContext.Current.Request.UserHostAddress

桌面:

//This one will bring all local IPs for the desired namespace
IPAddress[] localIPs = Dns.GetHostAddresses(Dns.GetHostName());

这个问题没有说ASP。NET MVC,但我还是把这个留在这里:

Request.UserHostAddress

以最快的方式获取远程ip地址。您必须使用下载程序,或者在您的计算机上创建一个服务器。

使用这段简单代码的缺点:(这是推荐的)是它将花费3-5秒来获取您的远程IP地址,因为web客户端初始化时总是需要3-5秒来检查您的代理设置。

 public static string GetIP()
 {
            string externalIP = "";
            externalIP = new WebClient().DownloadString("http://checkip.dyndns.org/");
            externalIP = (new Regex(@"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}"))
                                           .Matches(externalIP)[0].ToString();
            return externalIP;
 }

这是我如何修复它..(第一次仍然需要3-5秒),但在那之后,它总是会在0-2秒内得到你的远程IP地址,这取决于你的连接。

public static WebClient webclient = new WebClient();
public static string GetIP()
{
    string externalIP = "";
    externalIP = webclient.DownloadString("http://checkip.dyndns.org/");
    externalIP = (new Regex(@"\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}"))
                                   .Matches(externalIP)[0].ToString();
    return externalIP;
}

使用LINQ获取所有IP地址为字符串:

using System.Linq;
using System.Net.NetworkInformation;
using System.Net.Sockets;
...
string[] allIpAddresses = NetworkInterface.GetAllNetworkInterfaces()
    .SelectMany(c=>c.GetIPProperties().UnicastAddresses
        .Where(d=>d.Address.AddressFamily == AddressFamily.InterNetwork)
        .Select(d=>d.Address.ToString())
    ).ToArray();

为了过滤掉私人信息…

首先,定义一个扩展方法IsPrivate():

public static class IPAddressExtensions
{
    // Collection of private CIDRs (IpAddress/Mask) 
    private static Tuple<int, int>[] _privateCidrs = new []{"10.0.0.0/8", "172.16.0.0/12", "192.168.0.0/16"}
        .Select(c=>Tuple.Create(BitConverter.ToInt32(IPAddress
                                    .Parse(c.Split('/')[0]).GetAddressBytes(), 0)
                              , IPAddress.HostToNetworkOrder(-1 << (32-int.Parse(c.Split('/')[1])))))
        .ToArray();
    public static bool IsPrivate(this IPAddress ipAddress)
    {
        int ip = BitConverter.ToInt32(ipAddress.GetAddressBytes(), 0);
        return _privateCidrs.Any(cidr=>(ip & cidr.Item2)==(cidr.Item1 & cidr.Item2));           
    }
}

... 然后用它来过滤私人ip:

string[] publicIpAddresses = NetworkInterface.GetAllNetworkInterfaces()
    .SelectMany(c=>c.GetIPProperties().UnicastAddresses
        .Where(d=>d.Address.AddressFamily == AddressFamily.InterNetwork
            && !d.Address.IsPrivate() // Filter out private ones
        )
        .Select(d=>d.Address.ToString())
    ).ToArray();

这对我很有用……并且在大多数情况下(如果不是全部)应该比查询DNS服务器更快。多亏了《狡猾博士的学徒》。

// ************************************************************************
/// <summary>
/// Will search for the an active NetworkInterafce that has a Gateway, otherwise
/// it will fallback to try from the DNS which is not safe.
/// </summary>
/// <returns></returns>
public static NetworkInterface GetMainNetworkInterface()
{
    List<NetworkInterface> candidates = new List<NetworkInterface>();

    if (NetworkInterface.GetIsNetworkAvailable())
    {
        NetworkInterface[] NetworkInterfaces =
            NetworkInterface.GetAllNetworkInterfaces();

        foreach (
            NetworkInterface ni in NetworkInterfaces)
        {
            if (ni.OperationalStatus == OperationalStatus.Up)
                candidates.Add(ni);
        }
    }

    if (candidates.Count == 1)
    {
        return candidates[0];
    }

    // Accoring to our tech, the main NetworkInterface should have a Gateway 
    // and it should be the ony one with a gateway.
    if (candidates.Count > 1)
    {
        for (int n = candidates.Count - 1; n >= 0; n--)
        {
            if (candidates[n].GetIPProperties().GatewayAddresses.Count == 0)
            {
                candidates.RemoveAt(n);
            }
        }

        if (candidates.Count == 1)
        {
            return candidates[0];
        }
    }

    // Fallback to try by getting my ipAdress from the dns
    IPAddress myMainIpAdress = null;
    IPHostEntry host = Dns.GetHostEntry(Dns.GetHostName());
    foreach (IPAddress ip in host.AddressList)
    {
        if (ip.AddressFamily == AddressFamily.InterNetwork) // Get the first IpV4
        {
            myMainIpAdress = ip;
            break;
        }
    }

    if (myMainIpAdress != null)
    {
        NetworkInterface[] NetworkInterfaces =
            NetworkInterface.GetAllNetworkInterfaces();

        foreach (NetworkInterface ni in NetworkInterfaces)
        {
            if (ni.OperationalStatus == OperationalStatus.Up)
            {
                IPInterfaceProperties props = ni.GetIPProperties();
                foreach (UnicastIPAddressInformation ai in props.UnicastAddresses)
                {
                    if (ai.Address.Equals(myMainIpAdress))
                    {
                        return ni;
                    }
                }
            }
        }
    }

    return null;
}

// ******************************************************************
/// <summary>
/// AddressFamily.InterNetwork = IPv4
/// Thanks to Dr. Wilys Apprentice at
/// http://stackoverflow.com/questions/1069103/how-to-get-the-ip-address-of-the-server-on-which-my-c-sharp-application-is-runni
/// using System.Net.NetworkInformation;
/// </summary>
/// <param name="mac"></param>
/// <param name="addressFamily">AddressFamily.InterNetwork = IPv4,  AddressFamily.InterNetworkV6 = IPv6</param>
/// <returns></returns>
public static IPAddress GetIpFromMac(PhysicalAddress mac, AddressFamily addressFamily = AddressFamily.InterNetwork)
{
    NetworkInterface[] NetworkInterfaces =
        NetworkInterface.GetAllNetworkInterfaces();

    foreach (NetworkInterface ni in NetworkInterfaces)
    {
        if (ni.GetPhysicalAddress().Equals(mac))
        {
            if (ni.OperationalStatus == OperationalStatus.Up)
            {
                IPInterfaceProperties props = ni.GetIPProperties();
                foreach (UnicastIPAddressInformation ai in props.UnicastAddresses)
                {
                    if (ai.DuplicateAddressDetectionState == DuplicateAddressDetectionState.Preferred)
                    {
                        if (ai.Address.AddressFamily == addressFamily)
                        {
                            return ai.Address;
                        }
                    }
                }
            }
        }
    }

    return null;
}

// ******************************************************************
/// <summary>
/// Return the best guess of main ipAdress. To get it in the form aaa.bbb.ccc.ddd just call 
/// '?.ToString() ?? ""' on the result.
/// </summary>
/// <returns></returns>
public static IPAddress GetMyInternetIpAddress()
{
    NetworkInterface ni = GetMainNetworkInterface();
    IPAddress ipAddress = GetIpFromMac(ni.GetPhysicalAddress());
    if (ipAddress == null) // could it be possible ?
    {
        ipAddress = GetIpFromMac(ni.GetPhysicalAddress(), AddressFamily.InterNetworkV6);
    }

    return ipAddress;
}

// ******************************************************************

作为参考,这是我定义它的完整类代码:

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;
using System.Runtime.InteropServices;
using System.Threading.Tasks;

namespace TcpMonitor
{
    /*
        Usage:
                var cons = TcpHelper.GetAllTCPConnections();
                foreach (TcpHelper.MIB_TCPROW_OWNER_PID c in cons) ...
    */

    public class NetHelper
    {
        [DllImport("iphlpapi.dll", SetLastError = true)]
        static extern uint GetExtendedUdpTable(IntPtr pUdpTable, ref int dwOutBufLen, bool sort, int ipVersion, UDP_TABLE_CLASS tblClass, uint reserved = 0);

        public enum UDP_TABLE_CLASS
        {
            UDP_TABLE_BASIC,
            UDP_TABLE_OWNER_PID,
            UDP_TABLE_OWNER_MODULE
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_UDPTABLE_OWNER_PID
        {
            public uint dwNumEntries;
            [MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = 1)]
            public MIB_UDPROW_OWNER_PID[] table;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_UDPROW_OWNER_PID
        {
            public uint localAddr;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] localPort;
            public uint owningPid;

            public uint ProcessId
            {
                get { return owningPid; }
            }

            public IPAddress LocalAddress
            {
                get { return new IPAddress(localAddr); }
            }

            public ushort LocalPort
            {
                get { return BitConverter.ToUInt16(localPort.Take(2).Reverse().ToArray(), 0); }
            }
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_UDP6TABLE_OWNER_PID
        {
            public uint dwNumEntries;
            [MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = 1)]
            public MIB_UDP6ROW_OWNER_PID[] table;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_UDP6ROW_OWNER_PID
        {
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public byte[] localAddr;
            public uint localScopeId;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] localPort;
            public uint owningPid;
            public uint ProcessId
            {
                get { return owningPid; }
            }

            public IPAddress LocalAddress
            {
                get { return new IPAddress(localAddr, localScopeId); }
            }

            public ushort LocalPort
            {
                get { return BitConverter.ToUInt16(localPort.Take(2).Reverse().ToArray(), 0); }
            }
        }

        public static List<MIB_UDPROW_OWNER_PID> GetAllUDPConnections()
        {
            return GetUDPConnections<MIB_UDPROW_OWNER_PID, MIB_UDPTABLE_OWNER_PID> (AF_INET);
        }

        public static List<MIB_UDP6ROW_OWNER_PID> GetAllUDPv6Connections()
        {
            return GetUDPConnections<MIB_UDP6ROW_OWNER_PID, MIB_UDP6TABLE_OWNER_PID>(AF_INET6);
        }

        private static List<IPR> GetUDPConnections<IPR, IPT>(int ipVersion)//IPR = Row Type, IPT = Table Type
        {
            List<IPR> result = null;

            IPR[] tableRows = null;
            int buffSize = 0;

            var dwNumEntriesField = typeof(IPT).GetField("dwNumEntries");

            // how much memory do we need?
            uint ret = GetExtendedUdpTable(IntPtr.Zero, ref buffSize, true, ipVersion, UDP_TABLE_CLASS.UDP_TABLE_OWNER_PID);
            IntPtr udpTablePtr = Marshal.AllocHGlobal(buffSize);

            try
            {
                ret = GetExtendedUdpTable(udpTablePtr, ref buffSize, true, ipVersion, UDP_TABLE_CLASS.UDP_TABLE_OWNER_PID);
                if (ret != 0)
                    return new List<IPR>();

                // get the number of entries in the table
                IPT table = (IPT)Marshal.PtrToStructure(udpTablePtr, typeof(IPT));
                int rowStructSize = Marshal.SizeOf(typeof(IPR));
                uint numEntries = (uint)dwNumEntriesField.GetValue(table);

                // buffer we will be returning
                tableRows = new IPR[numEntries];

                IntPtr rowPtr = (IntPtr)((long)udpTablePtr + 4);
                for (int i = 0; i < numEntries; i++)
                {
                    IPR tcpRow = (IPR)Marshal.PtrToStructure(rowPtr, typeof(IPR));
                    tableRows[i] = tcpRow;
                    rowPtr = (IntPtr)((long)rowPtr + rowStructSize);   // next entry
                }
            }
            finally
            {
                result = tableRows?.ToList() ?? new List<IPR>();

                // Free the Memory
                Marshal.FreeHGlobal(udpTablePtr);
            }

            return result;
        }

        [DllImport("iphlpapi.dll", SetLastError = true)]
        static extern uint GetExtendedTcpTable(IntPtr pTcpTable, ref int dwOutBufLen, bool sort, int ipVersion, TCP_TABLE_CLASS tblClass, uint reserved = 0);



        public enum MIB_TCP_STATE
        {
            MIB_TCP_STATE_CLOSED = 1,
            MIB_TCP_STATE_LISTEN = 2,
            MIB_TCP_STATE_SYN_SENT = 3,
            MIB_TCP_STATE_SYN_RCVD = 4,
            MIB_TCP_STATE_ESTAB = 5,
            MIB_TCP_STATE_FIN_WAIT1 = 6,
            MIB_TCP_STATE_FIN_WAIT2 = 7,
            MIB_TCP_STATE_CLOSE_WAIT = 8,
            MIB_TCP_STATE_CLOSING = 9,
            MIB_TCP_STATE_LAST_ACK = 10,
            MIB_TCP_STATE_TIME_WAIT = 11,
            MIB_TCP_STATE_DELETE_TCB = 12
        }

        public enum TCP_TABLE_CLASS
        {
            TCP_TABLE_BASIC_LISTENER,
            TCP_TABLE_BASIC_CONNECTIONS,
            TCP_TABLE_BASIC_ALL,
            TCP_TABLE_OWNER_PID_LISTENER,
            TCP_TABLE_OWNER_PID_CONNECTIONS,
            TCP_TABLE_OWNER_PID_ALL,
            TCP_TABLE_OWNER_MODULE_LISTENER,
            TCP_TABLE_OWNER_MODULE_CONNECTIONS,
            TCP_TABLE_OWNER_MODULE_ALL
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_TCPTABLE_OWNER_PID
        {
            public uint dwNumEntries;
            [MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = 1)]
            public MIB_TCPROW_OWNER_PID[] table;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_TCP6TABLE_OWNER_PID
        {
            public uint dwNumEntries;
            [MarshalAs(UnmanagedType.ByValArray, ArraySubType = UnmanagedType.Struct, SizeConst = 1)]
            public MIB_TCP6ROW_OWNER_PID[] table;
        }

        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_TCPROW_OWNER_PID
        {
            public uint state;
            public uint localAddr;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] localPort;
            public uint remoteAddr;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] remotePort;
            public uint owningPid;

            public uint ProcessId
            {
                get { return owningPid; }
            }

            public IPAddress LocalAddress
            {
                get { return new IPAddress(localAddr); }
            }

            public ushort LocalPort
            {
                get
                {
                    return BitConverter.ToUInt16(new byte[2] { localPort[1], localPort[0] }, 0);
                }
            }

            public IPAddress RemoteAddress
            {
                get { return new IPAddress(remoteAddr); }
            }

            public ushort RemotePort
            {
                get
                {
                    return BitConverter.ToUInt16(new byte[2] { remotePort[1], remotePort[0] }, 0);
                }
            }

            public MIB_TCP_STATE State
            {
                get { return (MIB_TCP_STATE)state; }
            }
        }


        [StructLayout(LayoutKind.Sequential)]
        public struct MIB_TCP6ROW_OWNER_PID
        {
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public byte[] localAddr;
            public uint localScopeId;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] localPort;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 16)]
            public byte[] remoteAddr;
            public uint remoteScopeId;
            [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4)]
            public byte[] remotePort;
            public uint state;
            public uint owningPid;

            public uint ProcessId
            {
                get { return owningPid; }
            }

            public long LocalScopeId
            {
                get { return localScopeId; }
            }

            public IPAddress LocalAddress
            {
                get { return new IPAddress(localAddr, LocalScopeId); }
            }

            public ushort LocalPort
            {
                get { return BitConverter.ToUInt16(localPort.Take(2).Reverse().ToArray(), 0); }
            }

            public long RemoteScopeId
            {
                get { return remoteScopeId; }
            }

            public IPAddress RemoteAddress
            {
                get { return new IPAddress(remoteAddr, RemoteScopeId); }
            }

            public ushort RemotePort
            {
                get { return BitConverter.ToUInt16(remotePort.Take(2).Reverse().ToArray(), 0); }
            }

            public MIB_TCP_STATE State
            {
                get { return (MIB_TCP_STATE)state; }
            }
        }


        public const int AF_INET = 2;    // IP_v4 = System.Net.Sockets.AddressFamily.InterNetwork
        public const int AF_INET6 = 23;  // IP_v6 = System.Net.Sockets.AddressFamily.InterNetworkV6

        public static Task<List<MIB_TCPROW_OWNER_PID>> GetAllTCPConnectionsAsync()
        {
            return Task.Run(() => GetTCPConnections<MIB_TCPROW_OWNER_PID, MIB_TCPTABLE_OWNER_PID>(AF_INET));
        }

        public static List<MIB_TCPROW_OWNER_PID> GetAllTCPConnections()
        {
            return GetTCPConnections<MIB_TCPROW_OWNER_PID, MIB_TCPTABLE_OWNER_PID>(AF_INET);
        }

        public static Task<List<MIB_TCP6ROW_OWNER_PID>> GetAllTCPv6ConnectionsAsync()
        {
            return Task.Run(()=>GetTCPConnections<MIB_TCP6ROW_OWNER_PID, MIB_TCP6TABLE_OWNER_PID>(AF_INET6));
        }

        public static List<MIB_TCP6ROW_OWNER_PID> GetAllTCPv6Connections()
        {
            return GetTCPConnections<MIB_TCP6ROW_OWNER_PID, MIB_TCP6TABLE_OWNER_PID>(AF_INET6);
        }

        private static List<IPR> GetTCPConnections<IPR, IPT>(int ipVersion)//IPR = Row Type, IPT = Table Type
        {
            List<IPR> result = null;

            IPR[] tableRows = null;
            int buffSize = 0;

            var dwNumEntriesField = typeof(IPT).GetField("dwNumEntries");

            // how much memory do we need?
            uint ret = GetExtendedTcpTable(IntPtr.Zero, ref buffSize, true, ipVersion, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL);
            IntPtr tcpTablePtr = Marshal.AllocHGlobal(buffSize);

            try
            {
                ret = GetExtendedTcpTable(tcpTablePtr, ref buffSize, true, ipVersion, TCP_TABLE_CLASS.TCP_TABLE_OWNER_PID_ALL);
                if (ret != 0)
                    return new List<IPR>();

                // get the number of entries in the table
                IPT table = (IPT)Marshal.PtrToStructure(tcpTablePtr, typeof(IPT));
                int rowStructSize = Marshal.SizeOf(typeof(IPR));
                uint numEntries = (uint)dwNumEntriesField.GetValue(table);

                // buffer we will be returning
                tableRows = new IPR[numEntries];

                IntPtr rowPtr = (IntPtr)((long)tcpTablePtr + 4);
                for (int i = 0; i < numEntries; i++)
                {
                    IPR tcpRow = (IPR)Marshal.PtrToStructure(rowPtr, typeof(IPR));
                    tableRows[i] = tcpRow;
                    rowPtr = (IntPtr)((long)rowPtr + rowStructSize);   // next entry
                }
            }
            finally
            {
                result = tableRows?.ToList() ?? new List<IPR>();

                // Free the Memory
                Marshal.FreeHGlobal(tcpTablePtr);
            }

            return result;
        }

        public static string GetTcpStateName(MIB_TCP_STATE state)
        {
            switch (state)
            {
                case MIB_TCP_STATE.MIB_TCP_STATE_CLOSED:
                    return "Closed";
                case MIB_TCP_STATE.MIB_TCP_STATE_LISTEN:
                    return "Listen";
                case MIB_TCP_STATE.MIB_TCP_STATE_SYN_SENT:
                    return "SynSent";
                case MIB_TCP_STATE.MIB_TCP_STATE_SYN_RCVD:
                    return "SynReceived";
                case MIB_TCP_STATE.MIB_TCP_STATE_ESTAB:
                    return "Established";
                case MIB_TCP_STATE.MIB_TCP_STATE_FIN_WAIT1:
                    return "FinWait 1";
                case MIB_TCP_STATE.MIB_TCP_STATE_FIN_WAIT2:
                    return "FinWait 2";
                case MIB_TCP_STATE.MIB_TCP_STATE_CLOSE_WAIT:
                    return "CloseWait";
                case MIB_TCP_STATE.MIB_TCP_STATE_CLOSING:
                    return "Closing";
                case MIB_TCP_STATE.MIB_TCP_STATE_LAST_ACK:
                    return "LastAck";
                case MIB_TCP_STATE.MIB_TCP_STATE_TIME_WAIT:
                    return "TimeWait";
                case MIB_TCP_STATE.MIB_TCP_STATE_DELETE_TCB:
                    return "DeleteTCB";
                default:
                    return ((int)state).ToString();
            }
        }

        private static readonly ConcurrentDictionary<string, string> DicOfIpToHostName = new ConcurrentDictionary<string, string>();

        public const string UnknownHostName = "Unknown";

        // ******************************************************************
        public static string GetHostName(IPAddress ipAddress)
        {
            return GetHostName(ipAddress.ToString());
        }

        // ******************************************************************
        public static string GetHostName(string ipAddress)
        {
            string hostName = null;

            if (!DicOfIpToHostName.TryGetValue(ipAddress, out hostName))
            {
                try
                {
                    if (ipAddress == "0.0.0.0" || ipAddress == "::")
                    {
                        hostName = ipAddress;
                    }
                    else
                    {
                        hostName = Dns.GetHostEntry(ipAddress).HostName;
                    }
                }
                catch (Exception ex)
                {
                    Debug.Print(ex.ToString());
                    hostName = UnknownHostName;
                }

                DicOfIpToHostName[ipAddress] = hostName;
            }

            return hostName;
        }

        // ************************************************************************
        /// <summary>
        /// Will search for the an active NetworkInterafce that has a Gateway, otherwise
        /// it will fallback to try from the DNS which is not safe.
        /// </summary>
        /// <returns></returns>
        public static NetworkInterface GetMainNetworkInterface()
        {
            List<NetworkInterface> candidates = new List<NetworkInterface>();

            if (NetworkInterface.GetIsNetworkAvailable())
            {
                NetworkInterface[] NetworkInterfaces =
                    NetworkInterface.GetAllNetworkInterfaces();

                foreach (
                    NetworkInterface ni in NetworkInterfaces)
                {
                    if (ni.OperationalStatus == OperationalStatus.Up)
                        candidates.Add(ni);
                }
            }

            if (candidates.Count == 1)
            {
                return candidates[0];
            }

            // Accoring to our tech, the main NetworkInterface should have a Gateway 
            // and it should be the ony one with a gateway.
            if (candidates.Count > 1)
            {
                for (int n = candidates.Count - 1; n >= 0; n--)
                {
                    if (candidates[n].GetIPProperties().GatewayAddresses.Count == 0)
                    {
                        candidates.RemoveAt(n);
                    }
                }

                if (candidates.Count == 1)
                {
                    return candidates[0];
                }
            }

            // Fallback to try by getting my ipAdress from the dns
            IPAddress myMainIpAdress = null;
            IPHostEntry host = Dns.GetHostEntry(Dns.GetHostName());
            foreach (IPAddress ip in host.AddressList)
            {
                if (ip.AddressFamily == AddressFamily.InterNetwork) // Get the first IpV4
                {
                    myMainIpAdress = ip;
                    break;
                }
            }

            if (myMainIpAdress != null)
            {
                NetworkInterface[] NetworkInterfaces =
                    NetworkInterface.GetAllNetworkInterfaces();

                foreach (NetworkInterface ni in NetworkInterfaces)
                {
                    if (ni.OperationalStatus == OperationalStatus.Up)
                    {
                        IPInterfaceProperties props = ni.GetIPProperties();
                        foreach (UnicastIPAddressInformation ai in props.UnicastAddresses)
                        {
                            if (ai.Address.Equals(myMainIpAdress))
                            {
                                return ni;
                            }
                        }
                    }
                }
            }

            return null;
        }

        // ******************************************************************
        /// <summary>
        /// AddressFamily.InterNetwork = IPv4
        /// Thanks to Dr. Wilys Apprentice at
        /// http://stackoverflow.com/questions/1069103/how-to-get-the-ip-address-of-the-server-on-which-my-c-sharp-application-is-runni
        /// using System.Net.NetworkInformation;
        /// </summary>
        /// <param name="mac"></param>
        /// <param name="addressFamily">AddressFamily.InterNetwork = IPv4,  AddressFamily.InterNetworkV6 = IPv6</param>
        /// <returns></returns>
        public static IPAddress GetIpFromMac(PhysicalAddress mac, AddressFamily addressFamily = AddressFamily.InterNetwork)
        {
            NetworkInterface[] NetworkInterfaces =
                NetworkInterface.GetAllNetworkInterfaces();

            foreach (NetworkInterface ni in NetworkInterfaces)
            {
                if (ni.GetPhysicalAddress().Equals(mac))
                {
                    if (ni.OperationalStatus == OperationalStatus.Up)
                    {
                        IPInterfaceProperties props = ni.GetIPProperties();
                        foreach (UnicastIPAddressInformation ai in props.UnicastAddresses)
                        {
                            if (ai.DuplicateAddressDetectionState == DuplicateAddressDetectionState.Preferred)
                            {
                                if (ai.Address.AddressFamily == addressFamily)
                                {
                                    return ai.Address;
                                }
                            }
                        }
                    }
                }
            }

            return null;
        }

        // ******************************************************************
        /// <summary>
        /// Return the best guess of main ipAdress. To get it in the form aaa.bbb.ccc.ddd just call 
        /// '?.ToString() ?? ""' on the result.
        /// </summary>
        /// <returns></returns>
        public static IPAddress GetMyInternetIpAddress()
        {
            NetworkInterface ni = GetMainNetworkInterface();
            IPAddress ipAddress = GetIpFromMac(ni.GetPhysicalAddress());
            if (ipAddress == null) // could it be possible ?
            {
                ipAddress = GetIpFromMac(ni.GetPhysicalAddress(), AddressFamily.InterNetworkV6);
            }

            return ipAddress;
        }

        // ******************************************************************
        public static bool IsBroadcastAddress(IPAddress ipAddress)
        {
            if (ipAddress.AddressFamily == AddressFamily.InterNetwork)
            {
                return ipAddress.GetAddressBytes()[3] == 255;
            }

            if (ipAddress.AddressFamily == AddressFamily.InterNetworkV6)
            {
                return false; // NO broadcast in IPv6
            }

            return false;
        }

        // ******************************************************************
        public static bool IsMulticastAddress(IPAddress ipAddress)
        {
            if (ipAddress.AddressFamily == AddressFamily.InterNetwork)
            {
                // Source: https://technet.microsoft.com/en-us/library/cc772041(v=ws.10).aspx
                return ipAddress.GetAddressBytes()[0] >= 224 && ipAddress.GetAddressBytes()[0] <= 239;
            }

            if (ipAddress.AddressFamily == AddressFamily.InterNetworkV6)
            {
                return ipAddress.IsIPv6Multicast;
            }

            return false;
        }

        // ******************************************************************

    }
}

另一种获取公共IP地址的方法是使用OpenDNS的resolve1.opendns.com服务器,并将myip.opendns.com作为请求。

在命令行上,这是:

  nslookup myip.opendns.com resolver1.opendns.com

或者在c#中使用DNSClient nuget:

  var lookup = new LookupClient(new IPAddress(new byte[] { 208, 67, 222, 222 }));
  var result = lookup.Query("myip.opendns.com", QueryType.ANY);

这比敲击http端点并解析响应要简洁一些。


private static string GetLocalIpAdresse()
    {
        var host = Dns.GetHostEntry(Dns.GetHostName());
        foreach(var ip in host.AddressList)
        {
            if (ip.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
            {
                return ip.ToString();
            }
        }
        throw new Exception  ("No network adapters with an IPv4 address in the system");
    }