Question

我正在尝试在服务器收到＆＃34; debug＆＃34;时将数据发送回客户端。 ATM以下提供此错误：

不允许发送或接收数据的请求，因为套接字未连接且（使用sendto调用在数据报套接字上发送时）未提供地址。

添加了我的主要课程以帮助回答问题

    static Socket newSocket;
    static byte[] data;
    static EndPoint tmpRemote;
    static IPEndPoint sender, endpoint;
    static int recv;
    static void Main(string[] args)
    {
        data = new byte[1024];

        endpoint = new IPEndPoint(IPAddress.Any, 3000);

        newSocket = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);

        newSocket.Bind(endpoint);



        sender = new IPEndPoint(IPAddress.Any, 904);
        tmpRemote = (EndPoint)sender;

        newSocket.BeginReceiveFrom(data, 0, data.Length, SocketFlags.None, ref tmpRemote, new AsyncCallback(OperatorCallBack), data);

        Console.Read();
    }



    private static void OperatorCallBack(IAsyncResult ar)
    {
        log("[" + DateTime.Now + "][New Connection] " + tmpRemote.ToString() + "");
        try
        {
            int size = newSocket.EndReceiveFrom(ar, ref tmpRemote);
            if (size > 0)
            {
                data = (byte[])ar.AsyncState;
                string[] dataCommand = Encoding.ASCII.GetString(data, 0, size).Split(' ');
                if (dataCommand[0] == "debug")
                {
                    newSocket.Send(Encoding.ASCII.GetBytes("HA IT WORKED :)"));
                    log("Sent debug");
                }
                else
                {
                    log("Invalid Command");
                }
            }
            data = new byte[1024];
            newSocket.BeginReceiveFrom(data, 0, data.Length, SocketFlags.None, ref tmpRemote, new AsyncCallback(OperatorCallBack), data);
        }
        catch (Exception exp)
        {
            Console.WriteLine(exp.Message);
        }
    }

Answer 1

尝试通过慢速连接连接到套接字时遇到类似问题。我通过在任何发送/接收呼叫之前确保newSocket.Connected属性为真来解决它。

Answer 2

通过ProtocolType.Udp发送数据时不需要连接（socket.connect（））当您不建议UDP消息应转发的地址时，可能会发生该错误

在您的情况下 here the address is not provided for udp Send()

<强>解

尝试使用SendTo（）

Socket soc = new Socket(AddressFamily.InterNetwork, SocketType.Dgram, ProtocolType.Udp);
soc.EnableBroadcast = true;
IPEndPoint ipend = new IPEndPoint(IPAddress.Broadcast, 58717);
EndPoint endp = (EndPoint)ipend;
byte[] bytes = new byte[1024];

bytes = Encoding.ASCII.GetBytes(str);

soc.SendTo(bytes,ipend);

soc.Close();

Answer 3

错误信息非常清楚。您在未连接的套接字上调用send（）而不提供目标地址。你在哪里发送？ UDP不知道。

不允许发送或接收数据的请求，因为套接字未连接 - 发送数据时

3 个答案: