Question

有人可以使用UDP向我提供发送和接收广播消息的代码或链接吗？

我一直陷入困境，希望你能帮助我解决问题。感谢

Answer 1

这是一个C＃示例：

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;

class MainClass {
    static void Main(string[] args)
    {
        ThreadPool.QueueUserWorkItem(StartUDPListener);

        UdpClient udpClient = new UdpClient();
        udpClient.Send(new byte[]{0x00}, 1, new IPEndPoint(IPAddress.Broadcast, 4567));

        Console.ReadLine();
   }

   private static void StartUDPListener(object state) {
       UdpClient udpServer = new UdpClient(new IPEndPoint(IPAddress.Broadcast, 4567));

       IPEndPoint remoteEndPoint = null;
       udpServer.Receive(ref remoteEndPoint);

       Console.WriteLine("UDP broadcast received from " + remoteEndPoint + ".");   
   }
}

Answer 2

以下是广播发送者和接收者的示例代码。

它应该可以轻松移植到任何可以访问标准Berkly套接字API的语言。

#!/usr/bin/perl -w
# broadcast sender script
use strict;
use diagnostics;
use Socket;

my $sock;
my $receiverPort = 9722;
my $senderPort = 9721;

socket($sock, PF_INET, SOCK_DGRAM, getprotobyname('udp'))   || die "socket: $!";
setsockopt($sock, SOL_SOCKET, SO_REUSEADDR, pack("l", 1))   || die "setsockopt: $!";
setsockopt($sock, SOL_SOCKET, SO_BROADCAST, pack("l", 1)) or die "sockopt: $!";
bind($sock, sockaddr_in($senderPort, inet_aton('192.168.2.103')))  || die "bind: $!";

while (1) {
    my $datastring = `date`;
    my $bytes = send($sock, $datastring, 0, 
                     sockaddr_in($receiverPort, inet_aton('192.168.2.255')));
    if (!defined($bytes)) { 
        print("$!\n"); 
    } else { 
        print("sent $bytes bytes\n"); 
    }
    sleep(2);
}

#!/usr/bin/perl -w
# broadcast receiver script
use strict;
use diagnostics;
use Socket;

my $sock;

socket($sock, PF_INET, SOCK_DGRAM, getprotobyname('udp'))   || die "socket: $!";
setsockopt($sock, SOL_SOCKET, SO_REUSEADDR, pack("l", 1))   || die "setsockopt: $!";
bind($sock, sockaddr_in(9722, inet_aton('192.168.2.255')))  || die "bind: $!"; 

# just loop forever listening for packets
while (1) {
    my $datastring = '';
    my $hispaddr = recv($sock, $datastring, 64, 0); # blocking recv
    if (!defined($hispaddr)) {
        print("recv failed: $!\n");
        next;
    }
    print "$datastring";
}

Answer 3

我不打算发布代码，只是几个观察结果：

发送UDP广播就像发送单播数据包一样 - 只有目标地址不同。此可以为INADDR_BROADCAST（255.255.255.255），但这可能会导致具有多个网络接口的系统出现问题。最好发送到您要发送的接口的特定广播地址。唯一重要的警告是，在您的操作系统允许发送广播之前，您可能需要设置SO_BROADCAST套接字选项。
接收UDP广播完全就像接收单播数据包一样。不需要特殊代码，但您应该将接收器绑定到INADDR_ANY。

Answer 4

我刚刚开始学习这个，但这是我的第一个工作示例，它可能对你有帮助。

接收者代码：

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

class UDPReceiver
{
    static void Main(string[] args)
    {
        IPEndPoint endPoint;
        using (UdpClient client = new UdpClient(9998))
        {
            bool connected = true;
            while (connected)
            {
                byte[] dataBytes = client.Receive(ref endPoint);
                string dataString = Encoding.UTF8.GetString(dataBytes);

                if (dataString.ToLower() != "exit")
                    Console.WriteLine(dataString);
                else
                    connected = false;
            }
        }
    }
}

发件人代码：

using System;
using System.Net;
using System.Net.Sockets;
using System.Text;

class UDPSender
{
    static void Main(string[] args)
    {
        using (UdpClient client = new UdpClient())
        {
            bool connected = true;

            while (connected)
            {
                string dataString = Console.ReadLine();
                byte[] dataBytes = Encoding.UTF8.GetBytes(dataString);
                client.Send(dataBytes, dataBytes.Length, new IPEndPoint(IPAddress.Broadcast, 9998));
                if (dataString.ToLower() == "exit")
                    connected = false;
            }
        }
    }
}

广播

4 个答案:

接收者代码：

发件人代码：