使用异步套接字接收数据

时间:2015-04-16 05:37:03

标签: c# sockets beginreceive

我使用2种方式接收连接到IP地址的套接字数据。

  1. 同步接收。
  2. 异步接收。
  3. 使用同步接收,我在不到1秒的时间内从服务器获得所有响应。但是通过使用异步接收,接收所有响应需要30秒以上。

    以下是代码:

     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();
    }
    
        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
            {
                // 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);
                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.ReceiveTimeout = 500;
                    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)
            {
                MessageBox.Show(e.ToString());
            }
        }
    

1 个答案:

答案 0 :(得分:0)

在将当前字符串附加到缓冲区后,应该检查您的值,以便处理消息并删除client.ReceiveTimeout = 500;我认为这需要时间:

        if (bytesRead > 0)
        {
            state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));

            response = state.sb.ToString();
            if (response.IndexOf("<EOF>") != -1)
            {
                state.sb.Clear();
                receiveDone.Set();
            }
            else
            {
                client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
                    new AsyncCallback(ReceiveCallback), state);
            }
        }

这只适用于一条消息,对于实时多条消息,我认为你应该尝试不同的方法。