获取本地IP地址

在互联网上有几个地方告诉你如何获得一个IP地址。很多都像这个例子:

String strHostName = string.Empty;
// 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);
// 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());
}
Console.ReadLine();

在这个例子中，我得到了几个IP地址，但我只对路由器分配给运行程序的计算机的IP地址感兴趣:例如，如果某人希望访问我计算机中的共享文件夹，我将给他的IP地址。

如果我没有连接到网络，我直接通过没有路由器的调制解调器连接到互联网，那么我希望得到一个错误。我如何才能看到我的计算机是否连接到网络与c#，如果它是然后得到局域网IP地址。

当前回答

string str="";

System.Net.Dns.GetHostName();

IPHostEntry ipEntry = System.Net.Dns.GetHostEntry(str);

IPAddress[] addr = ipEntry.AddressList;

string IP="Your Ip Address Is :->"+ addr[addr.Length - 1].ToString();

2014-06-23 04:56:19

其他回答

用Linq更新Mrchief的答案，我们会有:

public static IPAddress GetLocalIPAddress()
{
   var host = Dns.GetHostEntry(Dns.GetHostName());
   var ipAddress= host.AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork);
   return ipAddress;
}

2018-02-26 08:39:27

当本地机器上有多个可用ip地址时，有一种更准确的方法。连接UDP套接字并读取其本地端点:

string localIP;
using (Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, 0))
{
    socket.Connect("8.8.8.8", 65530);
    IPEndPoint endPoint = socket.LocalEndPoint as IPEndPoint;
    localIP = endPoint.Address.ToString();
}

Connect on a UDP socket has the following effect: it sets the destination for Send/Recv, discards all packets from other addresses, and - which is what we use - transfers the socket into "connected" state, settings its appropriate fields. This includes checking the existence of the route to the destination according to the system's routing table and setting the local endpoint accordingly. The last part seems to be undocumented officially but it looks like an integral trait of Berkeley sockets API (a side effect of UDP "connected" state) that works reliably in both Windows and Linux across versions and distributions.

因此，此方法将提供用于连接到指定远程主机的本地地址。没有建立真正的连接，因此指定的远端ip不可达。

2014-12-09 10:13:33

已经有很多答案了，但我还是贡献我的一个:

public static IPAddress LocalIpAddress() {
    Func<IPAddress, bool> localIpPredicate = ip =>
        ip.AddressFamily == AddressFamily.InterNetwork &&
        ip.ToString().StartsWith("192.168"); //check only for 16-bit block
    return Dns.GetHostEntry(Dns.GetHostName()).AddressList.LastOrDefault(localIpPredicate);
}

一个衬套:

public static IPAddress LocalIpAddress() => Dns.GetHostEntry(Dns.GetHostName()).AddressList.LastOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork && ip.ToString().StartsWith("192.168"));

注意:从last开始搜索，因为它在一些接口添加到设备后仍然有效，如MobileHotspot,VPN或其他花哨的虚拟适配器。

2019-10-18 13:42:16

这是我发现的最好的代码，以获得当前的IP，避免获得VMWare主机或其他无效的IP地址。

public string GetLocalIpAddress()
{
    UnicastIPAddressInformation mostSuitableIp = null;

    var networkInterfaces = NetworkInterface.GetAllNetworkInterfaces();

    foreach (var network in networkInterfaces)
    {
        if (network.OperationalStatus != OperationalStatus.Up)
            continue;

        var properties = network.GetIPProperties();

        if (properties.GatewayAddresses.Count == 0)
            continue;

        foreach (var address in properties.UnicastAddresses)
        {
            if (address.Address.AddressFamily != AddressFamily.InterNetwork)
                continue;

            if (IPAddress.IsLoopback(address.Address))
                continue;

            if (!address.IsDnsEligible)
            {
                if (mostSuitableIp == null)
                    mostSuitableIp = address;
                continue;
            }

            // The best IP is the IP got from DHCP server
            if (address.PrefixOrigin != PrefixOrigin.Dhcp)
            {
                if (mostSuitableIp == null || !mostSuitableIp.IsDnsEligible)
                    mostSuitableIp = address;
                continue;
            }

            return address.Address.ToString();
        }
    }

    return mostSuitableIp != null 
        ? mostSuitableIp.Address.ToString()
        : "";
}

2016-11-10 13:27:36

这是最短的方法:

Dns.GetHostEntry(
    Dns.GetHostName()
).AddressList.AsEnumerable().Where(
    ip=>ip.AddressFamily.Equals(AddressFamily.InterNetwork)
).FirstOrDefault().ToString()

2021-10-17 16:24:06

获取本地IP地址

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