c# - 您如何获取默认网络适配器的主机广播地址？C＃

Question

假设我想向我的子网中的每个主机发送一条 udp 消息（然后从我的子网中的任何主机接收一条 udp 消息）：

目前我这样做：

IPAddress broadcast = IPAddress.Parse("192.168.1.255");

但我当然希望在子网不同于 192.168.1/24 的情况下动态地完成此操作。我试过：

IPAddress broadcast = IPAddress.Broadcast;

但 IPAddress.Broadcast 代表“255.255.255.255”，它不能用于发送消息（它会引发异常）......所以：

如何获取本地网络适配器广播地址（当然是网络掩码）？

这是我想出的最终解决方案

public IPAddress getBroadcastIP()
{
    IPAddress maskIP = getHostMask();
    IPAddress hostIP = getHostIP();

    if (maskIP==null || hostIP == null)
        return null;

    byte[] complementedMaskBytes = new byte[4];
    byte[] broadcastIPBytes = new byte[4];

    for (int i = 0; i < 4; i++)
    {
        complementedMaskBytes[i] =  (byte) ~ (maskIP.GetAddressBytes().ElementAt(i));
        broadcastIPBytes[i] = (byte) ((hostIP.GetAddressBytes().ElementAt(i))|complementedMaskBytes[i]);
    }

    return new IPAddress(broadcastIPBytes);

}


private IPAddress getHostMask()
{

    NetworkInterface[] Interfaces = NetworkInterface.GetAllNetworkInterfaces();

    foreach (NetworkInterface Interface in Interfaces)
    {

        IPAddress hostIP = getHostIP();

        UnicastIPAddressInformationCollection UnicastIPInfoCol = Interface.GetIPProperties().UnicastAddresses;

        foreach (UnicastIPAddressInformation UnicatIPInfo in UnicastIPInfoCol)
        {
            if (UnicatIPInfo.Address.ToString() == hostIP.ToString())
            {
                return UnicatIPInfo.IPv4Mask;
            }
        }
    }

    return null;
}

private IPAddress getHostIP()
{
    foreach (IPAddress ip in (Dns.GetHostEntry(Dns.GetHostName())).AddressList)
    {
        if (ip.AddressFamily == AddressFamily.InterNetwork)
            return ip;
    }

    return null;
}

Answer 1

如果你得到本地IP和子网，计算应该没有问题。

可能是这样的？

using System;
using System.Net.NetworkInformation;

public class test
{
    public static void Main()
    {
        NetworkInterface[] Interfaces = NetworkInterface.GetAllNetworkInterfaces();
        foreach(NetworkInterface Interface in Interfaces)
        {
            if(Interface.NetworkInterfaceType == NetworkInterfaceType.Loopback) continue;
            if (Interface.OperationalStatus != OperationalStatus.Up) continue;
            Console.WriteLine(Interface.Description);
            UnicastIPAddressInformationCollection UnicastIPInfoCol = Interface.GetIPProperties().UnicastAddresses;
            foreach(UnicastIPAddressInformation UnicatIPInfo in UnicastIPInfoCol)
            {
                Console.WriteLine("\tIP Address is {0}", UnicatIPInfo.Address);
                Console.WriteLine("\tSubnet Mask is {0}", UnicatIPInfo.IPv4Mask);
            }
        }
    }
}

给定IP地址和网络掩码时如何计算IP范围？应该给你剩下的。