c# - 发送或接收数据的请求被拒绝，因为套接字未连接。 .

Question

经过长时间的休息，我试图刷新我对 System.Net.Sockets 的内存，但我什至连 2 台机器都遇到了问题。

异常:发送或接收数据的请求被禁止，因为套接字未连接并且(当使用 sendto 调用在数据报套接字上发送时)没有提供地址

服务器代码:

private void startButton_Click(object sender, EventArgs e)
        {
            LocalEndpoint = new IPEndPoint(IPAddress.Parse("192.168.1.103"), 4444);
            _Socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            _Socket.Bind(LocalEndpoint);
            _Socket.Listen(10);
            _Socket.BeginAccept(new AsyncCallback(Accept), _Socket);
        }

private void Accept(IAsyncResult _IAsyncResult)
        {
            Socket AsyncSocket = (Socket)_IAsyncResult.AsyncState;
            AsyncSocket.EndAccept(_IAsyncResult);

            buffer = new byte[1024];

            AsyncSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(Receive), AsyncSocket);
        }

        private void Receive(IAsyncResult _IAsyncResult)
        {
            Socket AsyncSocket = (Socket)_IAsyncResult.AsyncState;
            AsyncSocket.EndReceive(_IAsyncResult);

            strReceive = Encoding.ASCII.GetString(buffer);

            Update_Textbox(strReceive);

            buffer = new byte[1024];

            AsyncSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(Receive), AsyncSocket);
        }

客户端代码:

 private void connectButton_Click(object sender, EventArgs e)
        {
            RemoteEndPoint = new IPEndPoint(IPAddress.Parse("192.168.1.103"), 4444);
            _Socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

            _Socket.BeginConnect(RemoteEndPoint, new AsyncCallback(Connect), _Socket);
        }

 private void Connect(IAsyncResult _IAsyncResult)
        {
            Socket RemoteSocket = (Socket)_IAsyncResult.AsyncState;
            RemoteSocket.EndConnect(_IAsyncResult);
        }

Answer 1

错误是由于您的 Accept 函数中的以下行:

AsyncSocket.EndAccept(_IAsyncResult);

服务器监听一个特定的套接字，并用它来接受来自客户端的连接。您不能使用相同的套接字来接受连接并从客户端接收数据。如果您查看 Socket.EndAccept 的帮助，它会说它创建了一个新的 Socket 来处理远程主机通信。在您的代码中，您使用 _Socket 来监听客户端连接和接收数据。您可以将此行修改为:

Socket dataSocket = AsyncSocket.EndAccept(_IAsyncResult);

您还需要将这个新套接字传递给 BeginReceive 函数参数:

AsyncSocket.BeginReceive(buffer, 0, buffer.Length, SocketFlags.None, new AsyncCallback(Receive), dataSocket);