Question

这是我的代码。我成功发送数据但没有收到任何数据。这是我的代码如下。我实际上是通过套接字发送23个字节并执行该事件，但是它没有收到数据服务器正在发回。我希望持久的双向连接来发送和接收数据

using System;
using System.Net;
using System.Net.Sockets;
using System.Threading;
using System.Text;
using System.Collections.Generic;

// State object for receiving data from remote device.
public class StateObject
{
    // Client socket.
    public Socket workSocket = null;
    // Size of receive buffer.
    public const int BufferSize = 256;
    // Receive buffer.
    public byte[] buffer = new byte[BufferSize];
    // Received data string.
    public StringBuilder sb = new StringBuilder();
}

public class AsynchronousClient
{
    // The port number for the remote device.
    private const int port = 18001;

    // ManualResetEvent instances signal completion.
    private static ManualResetEvent connectDone =
        new ManualResetEvent(false);
    private static ManualResetEvent sendDone =
        new ManualResetEvent(false);
    private static ManualResetEvent receiveDone =
        new ManualResetEvent(false);

    // The response from the remote device.
    private static String response = String.Empty;

    private static void StartClient()
    {
        // Connect to a remote device.
        try
        {


            IPEndPoint remoteEP = new IPEndPoint(IPAddress.Parse("192.168.1.140"), port);

            // Create a TCP/IP socket.
            Socket client = new Socket(AddressFamily.InterNetwork,SocketType.Stream, ProtocolType.Tcp);
            // Connect to the remote endpoint.
            client.BeginConnect(remoteEP, new AsyncCallback(ConnectCallback), client);
            connectDone.WaitOne();

            // Send test data to the remote device.
            Send(client, "This is a test<EOF>");
            sendDone.WaitOne();

            // Receive the response from the remote device.
            Receive(client);
            receiveDone.WaitOne();

            // Write the response to the console.
            Console.WriteLine("Response received : {0}", response);

            // Release the socket.
            client.Shutdown(SocketShutdown.Both);
            client.Close();

        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void ConnectCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.
            Socket client = (Socket)ar.AsyncState;

            // Complete the connection.
            client.EndConnect(ar);

            Console.WriteLine("Socket connected to {0}",
                client.RemoteEndPoint.ToString());

            // Signal that the connection has been made.
            connectDone.Set();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void Receive(Socket client)
    {
        try
        {
            // Create the state object.
            StateObject state = new StateObject();
            state.workSocket = client;

            // Begin receiving the data from the remote device.
            client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReceiveCallback), state);
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void ReceiveCallback(IAsyncResult ar)
    {
        try
        {

            StateObject state = (StateObject)ar.AsyncState;
            Socket client = state.workSocket;

            // Read data from the remote device.
            int bytesRead = client.EndReceive(ar);

            if (bytesRead > 0)
            {
                // There might be more data, so store the data received so far.
                state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

                // Get the rest of the data.
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
            else
            {
                // All the data has arrived; put it in response.
                if (state.sb.Length > 1)
                {
                    response = state.sb.ToString();
                }
                // Signal that all bytes have been received.
                receiveDone.Set();
            }
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    private static void Send(Socket client, String data)
    {

        // F2 00 DATA FF

        List<byte> byteTemp = new List<byte>();
        byteTemp.Add(0XF2);
        byteTemp.Add(0X00);


        byte[] TcpData = Encoding.ASCII.GetBytes("0040005001100180");
        foreach (byte eachdata in TcpData)
        {
            byteTemp.Add(eachdata);
        }

        byteTemp.Add(0XFF);

        byte[] byteData = byteTemp.ToArray();




        client.BeginSend(byteData, 0, byteData.Length, 0,
            new AsyncCallback(SendCallback), client);
    }

    private static void SendCallback(IAsyncResult ar)
    {
        try
        {
            // Retrieve the socket from the state object.
            Socket client = (Socket)ar.AsyncState;

            // Complete sending the data to the remote device.
            int bytesSent = client.EndSend(ar);
            Console.WriteLine("Sent {0} bytes to server.", bytesSent);

            // Signal that all bytes have been sent.
            sendDone.Set();
        }
        catch (Exception e)
        {
            Console.WriteLine(e.ToString());
        }
    }

    public static int Main(String[] args)
    {
        StartClient();
        return 0;
    }
}

Answer 1

private static void ReceiveCallback(IAsyncResult ar)
{     
    try
    {
        Console.WriteLine("Receieve Call Back Invoked");

        StateObject state = (StateObject)ar.AsyncState;
        Socket client = state.workSocket;

        // Read data from the remote device.
        int bytesRead = client.EndReceive(ar);
        Console.WriteLine("Receieve End Receieve");
        if (bytesRead > 0)
        {
            // There might be more data, so store the data received so far.
            state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
            Console.WriteLine("Read : " + bytesRead.ToString());
            // Get the rest of the data.
            client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                new AsyncCallback(ReceiveCallback), state);
            Console.WriteLine("Begin Receieve completed");
        }
        else
        {
            // All the data has arrived; put it in response.
            if (state.sb.Length > 1)
            {
                response = state.sb.ToString();
            }
            Console.WriteLine("Received data from client");
            // Signal that all bytes have been received.
            receiveDone.Set();
        }
        Console.WriteLine("completed receive callback");
    }
    catch (Exception e)
    {
        Console.WriteLine(e.ToString());
    }
}

已收到数据，但未使用，因为上述方法中的“else”未执行。

异步套接字C＃发送数据但未接收

1 个答案: