如何确定本地主机的IPv4地址?

IPAddress[] localIPs = Dns.GetHostAddresses(Dns.GetHostName());
private void get_IPs()
    {
        foreach (IPAddress a in localIPs)
        {
           server_ip = server_ip + a.ToString() + "/";
        }
    }

来自我的博客:

/// <summary> 
/// This utility function displays all the IP (v4, not v6) addresses of the local computer. 
/// </summary> 
public static void DisplayIPAddresses() 
{ 
    StringBuilder sb = new StringBuilder(); 
    // Get a list of all network interfaces (usually one per network card, dialup, and VPN connection) 
    NetworkInterface[] networkInterfaces = NetworkInterface.GetAllNetworkInterfaces(); 
    foreach (NetworkInterface network in networkInterfaces) 
    { 
        // Read the IP configuration for each network 
        IPInterfaceProperties properties = network.GetIPProperties(); 
        // Each network interface may have multiple IP addresses 
        foreach (IPAddressInformation address in properties.UnicastAddresses) 
        { 
            // We're only interested in IPv4 addresses for now 
            if (address.Address.AddressFamily != AddressFamily.InterNetwork) 
                continue; 
            // Ignore loopback addresses (e.g., 127.0.0.1) 
            if (IPAddress.IsLoopback(address.Address)) 
                continue; 
            sb.AppendLine(address.Address.ToString() + " (" + network.Name + ")"); 
        } 
    } 
    MessageBox.Show(sb.ToString()); 
}

特别地，我不推荐Dns.GetHostAddresses(Dns.GetHostName());，不管这句话在各种文章和博客上有多流行。

在您的代码中添加如下内容

  if( IPAddress.Parse(a).AddressFamily == AddressFamily.InterNetwork )
  // IPv4 address

下面是我使用的一个函数:

public static string GetIP4Address()
{
    string IP4Address = String.Empty;
    foreach (IPAddress IPA in Dns.GetHostAddresses(Dns.GetHostName()))
    {
        if (IPA.AddressFamily == AddressFamily.InterNetwork)
        {
            IP4Address = IPA.ToString();
            break;
        }
    }
    return IP4Address;
}

---

作为可枚举对象:

public static IEnumerable<string> GetIP4Addresses()
{
    return Dns.GetHostAddresses(Dns.GetHostName())
        .Where(IPA => IPA.AddressFamily == AddressFamily.InterNetwork)
        .Select(x => x.ToString());
}

使用Linq时非常干净和甜蜜

IPAddress[] addresses = Dns.GetHostAddresses(Dns.GetHostName()).Where(a => a.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork).ToArray();

写locaIPs.Where(ip => ip.AddressFamily == AddressFamily.InterNetwork)

From MSDN on Dns。GetHostAddresses,

当传递一个空字符串作为主机名时，此方法返回所有操作系统的本地主机IPv4地址Windows Server 2003;对于Windows Server 2003，支持IPv4和IPv6返回本地主机的地址。

IPv6地址从GetHostAddresses的结果中过滤如果本地计算机没有安装IPv6，请使用此方法。作为一个结果，有可能返回一个空的IPAddress实例，如果只有

hostnameoraddress .参数可用的IPv6结果。

那么，你可以用这个来试着解析它:

IPAddress.TryParse

检查AddressFamily

返回System.Net.Sockets.AddressFamily.InterNetwork为IPv4或System.Net.Sockets.AddressFamily。InterNetworkV6 for IPv6.

string input = "192.168.0.10";
IPAddress address;
if (IPAddress.TryParse(input, out address))
{
    switch (address.AddressFamily)
    {
        case System.Net.Sockets.AddressFamily.InterNetwork:
            // we have IPv4
            break;
        case System.Net.Sockets.AddressFamily.InterNetworkV6:
            // we have IPv6
            break;
        default:
            // do something else
            break;
    }
}

我使用了以

开头的答案

/// <summary> and it mostly worked:
//for some reason Visual Studio 2010 did not understand AddressFamily.Inernetwork
    if (address.Address.AddressFamily != AddressFamily.InterNetwork) 

我不得不使用:

if(address.Address.AddressFamily != System.Net.Sockets.AddressFamily.InterNetwork)

但我实际上用的是:

if(!address.Address.AddressFamily.Equals(System.Net.Sockets.AddressFamily.InterNetwork))

我还加上了:

if (network.OperationalStatus != OperationalStatus.Up)
                continue;

因为有一些网络不工作，不应该在那里，我确实看到他们在注册表中。——阿尔文

我使用这个helper方法，它在过滤掉IPV6和环回一次后返回第一个活动IPV4地址

    public static IPAddress GetLocalIPAddress()
    {
        IPAddress result = null;
        IPHostEntry iphostentry = Dns.GetHostEntry(Dns.GetHostName());
        IPAddress[] ipv4Address = Array.FindAll(iphostentry.AddressList, add => add.AddressFamily == AddressFamily.InterNetwork && !IPAddress.IsLoopback(add));
        if (ipv4Address.Length > 0 )
        {
            result =ipv4Address[0];
        }
        return result;
    }

对我来说更简洁的解决方案是:

 public static string GetLocalIP() 
        {
            string ipv4Address = String.Empty;
            foreach (IPAddress currentIPAddress in Dns.GetHostAddresses(Dns.GetHostName()))
            {
                if (currentIPAddress.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork)
                {
                    ipv4Address = currentIPAddress.ToString();
                    break;
                }
            }
            return ipv4Address;
        }

这是我的代码。并且可以在许多局域网卡上找到它。

private string GetLocalIpAddress()
{
    string localIpAddress = string.Empty;
    NetworkInterface[] nics = NetworkInterface.GetAllNetworkInterfaces();
    foreach (NetworkInterface nic in nics)
    {
        if (nic.OperationalStatus != OperationalStatus.Up)
        {
            continue;
        }
        IPv4InterfaceStatistics adapterStat = (nic).GetIPv4Statistics();
        UnicastIPAddressInformationCollection uniCast = (nic).GetIPProperties().UnicastAddresses;
        if (uniCast != null)
        {
            foreach (UnicastIPAddressInformation uni in uniCast)
            {
                if (adapterStat.UnicastPacketsReceived > 0
                    && adapterStat.UnicastPacketsSent > 0
                    && nic.NetworkInterfaceType != NetworkInterfaceType.Loopback)
                {
                    if (uni.Address.AddressFamily == AddressFamily.InterNetwork)
                    {
                        localIpAddress = nic.GetIPProperties().UnicastAddresses[0].Address.ToString();
                        break;
                    }
                }
            }
        }
    }
    return localIpAddress;
}

下面是使用for循环查找第一个连接的IPv4的代码:

        IPAddress ipAddress = null;
        IPAddress[] localIPs = Dns.GetHostAddresses(Dns.GetHostName());           
        for (int i=0 ; i<localIPs.Length ; i++)
        {
            if (localIPs[i].AddressFamily == AddressFamily.InterNetwork)
            {
                ipAddress = localIPs[i];
                break;
            }                
        }