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();
        }
    }
}

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。

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;
}

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。

试试这个:

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