unity udp广播 发送和接收

要在Unity中实现UDP广播的发送和接收，可以使用C#中的Socket类，以下是一个示例代码：

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

public class UdpBroadcastSender : MonoBehaviour
{
    private const int PORT = 12345;

    private UdpClient udpClient;

    private void Start()
    {
        udpClient = new UdpClient();
        udpClient.EnableBroadcast = true;
        udpClient.Client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.ReuseAddress, true);
        udpClient.Client.Bind(new IPEndPoint(IPAddress.Any, PORT));
    }

    private void OnDestroy()
    {
        udpClient.Close();
    }

    public void SendMessage(string message)
    {
        byte[] data = Encoding.ASCII.GetBytes(message);
        udpClient.Send(data, data.Length, new IPEndPoint(IPAddress.Broadcast, PORT));
    }
}

public class UdpBroadcastReceiver : MonoBehaviour
{
    private const int PORT = 12345;

    private UdpClient udpClient;
    private IPEndPoint ipEndPoint;

    private void Start()
    {
        udpClient = new UdpClient(PORT);
        ipEndPoint = new IPEndPoint(IPAddress.Any, PORT);
        udpClient.EnableBroadcast = true;
        udpClient.MulticastLoopback = true;
        udpClient.JoinMulticastGroup(IPAddress.Broadcast);
        udpClient.BeginReceive(new AsyncCallback(OnReceive), null);
    }

    private void OnDestroy()
    {
        udpClient.Close();
    }

    private void OnReceive(IAsyncResult result)
    {
        byte[] data = udpClient.EndReceive(result, ref ipEndPoint);
        string message = Encoding.ASCII.GetString(data);
        Debug.Log("Received message: " + message);
        udpClient.BeginReceive(new AsyncCallback(OnReceive), null);
    }
}

在以上代码中，UdpBroadcastSender类用来发送UDP广播消息，UdpBroadcastReceiver类用来接收UDP广播消息。在UdpBroadcastReceiver类中，我们使用了异步回调的方式来接收消息，这样可以保证在接收到消息之前不会阻塞主线程。

在Unity中，你可以将上述代码分别添加到两个不同的GameObject上，并在需要发送广播消息的时候调用UdpBroadcastSender.SendMessage函数即可。同时，在接收到广播消息时，UdpBroadcastReceiver.OnReceive函数会被自动调用，你可以在这个函数中处理接收到的消息。