c# - C#异步套接字不会返回整页

Question

这是我的创建套接字部分:

_client = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
_client.BeginConnect(_IPEnd, new AsyncCallback(ConnectCallback), _client);
connectDone.WaitOne();
Send(_client, "GET / HTTP/1.1\r\nHost: www.google.de\r\nConnection: Keep-Alive\r\n\r\n");

接收部分:

private void Receive()
    {
        // Create the state object.
        StateObject state = new StateObject();
        state.workSocket = _client;

        // Begin receiving the data from the remote device.
        _client.BeginReceive(state.buffer, 0, state.buffer.Length , 0, new AsyncCallback(ReceiveCallback), state);
    }

private void ReceiveCallback(IAsyncResult ar)
    {
        // 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));

            client.BeginReceive(state.buffer,0,state.buffer.Length, 0, new AsyncCallback(ReceiveCallback), state);
        }
        else 
        {
            state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead)); 
            int length = state.sb.ToString().Length;
            ProcessData(state.sb.ToString());

            receiveDone.Set();
        }

    }

缓冲区

    public class StateObject
    {
        private Guid ID = Guid.NewGuid();
        // Client socket.
        public Socket workSocket = null;
        // Size of receive buffer.
        public const int BufferSize = 4096;
        // Receive buffer.
        public byte[] buffer = new byte[BufferSize];

        public StringBuilder sb = new StringBuilder();
    }

为什么此代码不返回整页？

recvcallback的这部分有什么问题吗

if (bytesRead > 0)

Answer 1

您似乎在假定仅当缓冲区已满或连接已关闭时才回叫您。事实并非如此。您可能有一个8K的缓冲区，并且从服务器发送了20K的数据，在10个调用中，每个读取为2K。

假设您要读取直到关闭连接为止，您应该继续进行直到client.EndReceive返回0。(对于具有keepalive的HTTP，您需要读取内容长度并继续进行，直到读取了体内的大量数据为止。 )

编辑:我刚刚看到您在连接上设置了Keep-Alive。如果您希望服务器关闭连接以告诉您它已完成，请不要这样做!

(当然，总的来说，最好使用HTTP库来完成所有这些工作-为什么要编写自己的HTTP处理代码？)