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我從幾個例子中拉出來設置連接到服務器的全雙工C#TCP客戶端。基本概念是客戶端和服務器都發送/接收消息(命令和事件)。因此,我開發了一個FullDuplexSocket類,它公開發送消息到服務器的Send方法以及從服務器接收消息的事件處理程序。除了我似乎無法清除從服務器接收到的消息緩衝區之外,一切正常。每次服務器發送新消息時,套接字中的緩衝區都包含新消息(已讀取)和。我可以通過已知的分隔符(/ r/n)分割消息並對其進行跟蹤,但這可能會成爲長時間運行的通信中存儲器問題的根源。 [編輯:將代碼更新爲不再存在緩衝區問題並可正常工作的解決方案]。如何「刷新」TCP客戶端緩衝區?
有沒有人有任何建議。總重寫?代碼如下,希望能幫助其他人。
這裏的FullDuplexSocket類:
using System;
using System.Text;
using System.Net.Sockets;
namespace Utilities
{
public class StateObject{
public Socket workSocket = null;
public const int BUFFER_SIZE = 1024;
public byte[] buffer = new byte[BUFFER_SIZE];
}
public class FullDuplexSocket : IDisposable
{
public event NewMessageHandler OnMessageReceived;
public delegate void NewMessageHandler(string Message);
public event DisconnectHandler OnDisconnect;
public delegate void DisconnectHandler(string Reason);
private Socket _socket;
private bool _useASCII = true;
private string _remoteServerIp = "";
private int _port = 0;
/// <summary>
/// Constructer of a full duplex client socket. The consumer should immedately define
/// and event handler for the OnMessageReceived event after construction has completed.
/// </summary>
/// <param name="RemoteServerIp">The remote Ip address of the server.</param>
/// <param name="Port">The port that will used to transfer/receive messages to/from the remote IP.</param>
/// <param name="UseASCII">The character type to encode/decode messages. Defaulted to use ASCII, but setting the value to false will encode/decode messages in UNICODE.</param>
public FullDuplexSocket(string RemoteServerIp, int Port, bool UseASCII = true)
{
_useASCII = UseASCII;
_remoteServerIp = RemoteServerIp;
_port = Port;
try //to create the socket and connect
{
_socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
_socket.Connect(RemoteServerIp, _port);
}
catch (Exception e)
{
throw new Exception("Unable to connect to the remote Ip.", e);
}
try //to listen to the socket
{
StateObject stateObject = new StateObject();
stateObject.workSocket = _socket;
_socket.BeginReceive
(
stateObject.buffer, //Buffer to load in our state object
0, //Start at the first position in the byte array
StateObject.BUFFER_SIZE, //only load up to the max per read
0, //Set socket flags here if necessary
new AsyncCallback(ReadFromSocket), //Who to call when data arrives
stateObject //state object to use when data arrives
);
}
catch (Exception e)
{
throw new Exception("Unable to start listening to the socket.", e);
}
}
/// <summary>
/// This will read the bytes from the socket, convert the bytes to a string and fire the OnMessageReceived event.
/// If the socket is forcibly closed, the OnDisconnect event will be fired. This happens when the other side of
/// the socket connection on the remote Ip is no longer available.
/// </summary>
/// <param name="asyncResult"></param>
public void ReadFromSocket(IAsyncResult asyncResult)
{
StateObject stateObject = (StateObject)asyncResult.AsyncState; //pull out the state object
int bytesReceived = 0;
try //to receive the message.
{
bytesReceived = stateObject.workSocket.EndReceive(asyncResult);
}
catch (Exception e) //Exception will occur if connection was forcibly closed.
{
RaiseOnDisconnect(e.Message);
return;
}
if (bytesReceived > 0)
{
RaiseOnMessageReceived
(
_useASCII ?
Encoding.ASCII.GetString(stateObject.buffer, 0, bytesReceived) :
Encoding.Unicode.GetString(stateObject.buffer, 0, bytesReceived)
);
stateObject.workSocket.BeginReceive
(
stateObject.buffer, //Buffer to load in our state object
0, //Start at the first position in the byte array
StateObject.BUFFER_SIZE, //only load up to the max per read
0, //Set socket flags here if necessary
new AsyncCallback(ReadFromSocket), //Who to call when data arrives
stateObject //state object to use when data arrives
);
}
else
{
stateObject.workSocket.Close();
RaiseOnDisconnect("Socket closed normally.");
return;
}
}
/// <summary>
/// Broadcast a message to the IP/Port. Consumer should handle any exceptions thrown by the socket.
/// </summary>
/// <param name="Message">The message to be sent will be encoded using the character set defined during construction.</param>
public void Send(string Message)
{
//all messages are terminated with /r/n
Message += Environment.NewLine;
byte[] bytesToSend = _useASCII ?
Encoding.ASCII.GetBytes(Message) :
Encoding.Unicode.GetBytes(Message);
int bytesSent = _socket.Send(bytesToSend);
}
/// <summary>
/// Clean up the socket.
/// </summary>
void IDisposable.Dispose()
{
try
{
_socket.Close();
RaiseOnDisconnect("Socket closed via Dispose method.");
}
catch { }
try
{
_socket.Dispose();
}
catch { }
}
/// <summary>
/// This method will gracefully raise any delegated events if they exist.
/// </summary>
/// <param name="Message"></param>
private void RaiseOnMessageReceived(string Message)
{
try //to raise delegates
{
OnMessageReceived(Message);
}
catch { } //when none exist ignore the Object Reference Error
}
/// <summary>
/// This method will gracefully raise any delegated events if they exist.
/// </summary>
/// <param name="Message"></param>
private void RaiseOnDisconnect(string Message)
{
try //to raise delegates
{
OnDisconnect(Message);
}
catch { } //when none exist ignore the Object Reference Error
}
}
}
類的消費者將簡單地做到以下幾點:
using System;
namespace Utilities
{
public class SocketConsumer
{
private FullDuplexSocket _fds;
public Consumer()
{
_fds = new FullDuplexSocket("192.168.1.103", 4555);
_fds.OnMessageReceived += fds_OnMessageReceived;
_fds.Send("Hello World!");
}
void fds_OnMessageReceived(string Message)
{
Console.WriteLine("Message: {0}", Message);
}
}
}
任何幫助將是巨大的。謝謝!
感謝您的回覆。單步執行代碼,計數似乎設置爲1029990765,並且始終大於bytesRead。不清楚在這裏等待的使用,也許一個例子可能有所幫助?也許我有一些邏輯落後? –
不知道那裏發生了什麼,但爲什麼計數等於〜10億?這是一個錯誤。添加運行時斷言以捕獲發生該情況的最早情況。等待填充不會立即解決問題 - 它會盡可能簡化代碼(根本不需要回調),這樣錯誤就會變得明顯。我也很想把更多的時間投入到意大利麪條的回調中。這不是你的錯 - 這只是回調驅動代碼的本質。 – usr
經過多次迭代,我將問題中的代碼編輯爲可行的解決方案。從遠程服務器接收到每條消息後,緩衝區將被清除,並且一切正常。我無法確定使用Async/await來解決這個問題的方法,所以醜陋的回調仍然存在,但似乎在.NET的Socket類的實現中正確使用。歡迎任何其他意見/替代解決方案。 ...感謝usr ... –