Question

我尝试用异步套接字通信实现我的应用程序。它完美地连接并发送请求但我没有从服务器（Java服务器）接收任何数据。套接字连接

client.BeginConnect(hostname, port,
            new AsyncCallback(ConnectCallback), client);
connectDone.WaitOne();

  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, SocketFlags.None,
            new AsyncCallback(ReceiveCallback), client);
    }
    catch (Exception e)
    {
        Console.WriteLine(e.ToString());
    }
}

private static void ReceiveCallback(IAsyncResult ar)
{
    try
    {
        // Retrieve the state object and the client socket 
        // from the asynchronous state object.
        StateObject state = (StateObject)ar.AsyncState;
        Socket client = state.workSocket;

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

任何帮助都将不胜感激。

Answer 1

你的代码几乎没问题，有一个严重的错误。在BeginReceive中，您将客户端套接字实例作为状态对象。在ReceiveCallback函数中，您将其强制转换为StateObject而不是套接字。这将导致在控制台上显示异常。

然而，对于这个错误，将触发ReceiveCallback函数开头的断点。你试过这个吗？无论如何都应该抛出异常。

如果断点未触发，则应独立检查是否确实从服务器发送了某些内容。当然，正如你所说的，所有假设连接都有效。

异步客户端套接字不接收数据

1 个答案: