我一直在尝试使用TCP为我正在构建的应用程序编写通信层。我控制服务器端和客户端操作。
我遇到的问题是当我使用＆＃39; localhost＆＃39;作为我的知识产权，我没有问题。然而，当我使用互联网连接时，一切都神奇地工作......第一次。当客户端尝试与服务器建立另一个套接字连接时，在ReadCallback期间，我在服务器端获得SocketException ErrorCode 10054，特别是当我执行socket.EndReceive操作时。
我已经看过我的套接字没有得到正确处理的可能性 - 他们肯定应该这样，因为我看不到客户端或服务器端应用程序的路径，这些路径不会导致关闭。< / p>
我的代码非常类似于MSDN中的代码，可以找到here (server)和here (client)
以下是我的客户代码的相关部分：
public class ClientStateObject
{
// Client socket.
public Socket workSocket = null;
// Receive buffer.
public byte[] buffer = new byte[Constants.ClientBuffer];
// Received data string.
public StringBuilder sb = new StringBuilder();
public List<byte[]> Data = new List<byte[]>();
}
public class AsynchronousClient
{
// 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 byte[] response = null;
public static object StartClient(object sendObj)
{
// Connect to a remote device.
try
{
// Establish the remote endpoint for the socket.
// The name of the
// remote device is ...
IPHostEntry ipHostInfo = Dns.Resolve(Constants.Hostname); // localhost
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint remoteEP = new IPEndPoint(ipAddress, Constants.Port);
// Create a TCP/IP socket.
Socket client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
LingerOption lo = new LingerOption(false, 0);
client.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, lo);
// Connect to the remote endpoint.
client.BeginConnect(remoteEP,
new AsyncCallback(ConnectCallback), client);
connectDone.WaitOne();
// Send test data to the remote device.
object[] s;
s = new object[2] { sendObj, "<EOF>" };
Send(client, s);
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);
//Console.ReadKey();
// Release the socket.
client.Shutdown(SocketShutdown.Both);
client.Close();
//object res = Deserialize(Deserialize(response) as byte[]);
object res = Deserialize(Deserialize(response) as byte[]);
return res;
}
catch (Exception e)
{
return e;
}
}
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.
ClientStateObject state = new ClientStateObject();
state.workSocket = client;
// Begin receiving the data from the remote device.
client.BeginReceive(state.buffer, 0, Constants.ClientBuffer, 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.
ClientStateObject state = (ClientStateObject)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));
state.Data.Add(state.buffer); // Concat byte[] to received packet
// Get the rest of the data.
client.BeginReceive(state.buffer, 0, Constants.ClientBuffer, 0,
new AsyncCallback(ReceiveCallback), state);
}
else
{
// All the data has arrived; put it in response.
if (state.sb.Length > 1)
{
response = ConcatByteListToArray(state.Data);
}
// Signal that all bytes have been received.
receiveDone.Set();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static byte[] ConcatByteListToArray(List<byte[]> b)
{
List<byte> bList = new List<byte>();
foreach (byte[] bA in b)
{
foreach (byte by in bA)
{
bList.Add(by);
}
}
return bList.ToArray();
}
private static void Send(Socket client, object data)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Serialize(data);
// Begin sending the data to the remote device.
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());
}
}
/*
* Function: Serialize(object obj)
* Requires: Arbitrary object.
* Returns: MyMessage object, which constants a byte[] (Data) representing an object in TCP-friendly form.
* Description: Private function used to turn an object into a serialized byte[].
*/
private static byte[] Serialize(object obj)
{
using (var memoryStream = new MemoryStream())
{
(new BinaryFormatter()).Serialize(memoryStream, obj);
return memoryStream.ToArray();
}
}
/*
* Function: Deserialize(MyMessage message)
* Requires: MyMessage object with Data attribute.
* Returns: object which was originally serialized.
* Description: Private function used to reverse the process of "Serialize".
*/
private static object Deserialize(byte[] message)
{
using (var memoryStream = new MemoryStream(message))
{
return (new BinaryFormatter()).Deserialize(memoryStream);
}
}
以下是服务器代码的相关部分：
public class ServerStateObject
{
// Client socket.
public Socket workSocket = null;
// Receive buffer.
public byte[] buffer = new byte[Constants.ServerBuffer];
// Received data string.
public StringBuilder sb = new StringBuilder();
public List<byte[]> Data = new List<byte[]>();
}
public class AsynchronousSocketListener
{
public static bool GetDataSuccess;
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
public AsynchronousSocketListener()
{
}
public static void StartListening()
{
// Data buffer for incoming data.
byte[] bytes = new Byte[Constants.ServerBuffer];
// Establish the local endpoint for the socket.
// The DNS name of the computer
// running the listener is "host.contoso.com".
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Any, Constants.Port);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
LingerOption lo = new LingerOption(false, 0);
listener.SetSocketOption(SocketOptionLevel.Socket, SocketOptionName.Linger, lo);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
listener.Bind(localEndPoint);
listener.Listen(10);
while (true)
{
// Set the event to nonsignaled state.
allDone.Reset();
// Start an asynchronous socket to listen for connections.
Console.WriteLine("Waiting for a connection...");
listener.BeginAccept(
new AsyncCallback(AcceptCallback),
listener);
// Wait until a connection is made before continuing.
allDone.WaitOne();
//Console.WriteLine("Done waiting for client.");
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
public static void AcceptCallback(IAsyncResult ar)
{
// Signal the main thread to continue.
allDone.Set();
// Get the socket that handles the client request.
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
// Create the state object.
ServerStateObject state = new ServerStateObject();
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, Constants.ServerBuffer, 0,
new AsyncCallback(ReadCallback), state);
}
public static void ReadCallback(IAsyncResult ar)
{
String content = String.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
ServerStateObject state = (ServerStateObject)ar.AsyncState;
Socket handler = state.workSocket;
Console.WriteLine("Read {0} bytes from {1} : {2}.",
content.Length, (handler.LocalEndPoint as IPEndPoint).Address, (handler.LocalEndPoint as IPEndPoint).Port);
int bytesRead = 0;
try
{
bytesRead = handler.EndReceive(ar);
}
catch (SocketException se)
{
Console.WriteLine("Socket Exception in Callback Read: {0}", se.ErrorCode); // I always get an error here on refresh
}
// Read data from the client socket.
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)); // Check if there is an EOF in the byte[]
state.Data.Add(state.buffer); // Concat byte[] to received packet
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
byte[] rArray = ConcatByteListToArray(state.Data);
byte[] sendArray = Serialize(HandleRead(rArray));
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from {1} : {2}.",
content.Length, (handler.LocalEndPoint as IPEndPoint).Address, (handler.LocalEndPoint as IPEndPoint).Port);
// Echo the data back to the client.
Send(handler, sendArray);
}
else
{
// Not all data received. Get more.
handler.BeginReceive(state.buffer, 0, Constants.ServerBuffer, 0,
new AsyncCallback(ReadCallback), state);
}
}
}
private static void Send(Socket handler, object data)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Serialize(data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,
new AsyncCallback(SendCallback), handler);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
Socket handler = (Socket)ar.AsyncState;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
Console.WriteLine("Sent {0} bytes to client.", bytesSent);
handler.Shutdown(SocketShutdown.Both);
handler.Close();
Console.WriteLine("Connection to client broken.");
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
我认为问题可能与Windows处理套接字的方式有关，也许还没有那么快。遗憾的是，即使我在第一次和第二次连接之间等待几分钟，代码也无法进行刷新。
答案 0 :(得分：2)
好的，经过我的代码搜索和阅读错误消息后，我发现客户端在进入“发送”之前抛出了错误代码10057。此错误意味着套接字未打开 - 即使套接字应该等待发送直到套接字打开。
因此，问题是事件在程序的每次运行开始时都没有重置。这在localhost上不是问题，因为异步套接字能够在到达需要打开的send函数中的某个点之前打开。但是，当终点不是本地时，它花了太长时间，因此错误。
我只是在“StartClient”的开头添加了三行代码：
connectDone.Reset();
sendDone.Reset();
receiveDone.Reset();
这解决了整个问题。
所以...总是记得设置你的初始变量条件，以免你看起来像个傻瓜！