基本上我制作了两个C＃应用程序，一个客户端和一个服务器。客户端连接到服务器（通过套接字），然后发送包含一些文本的数据包，服务器应该回复。 我的问题是：服务器仅在关闭时发送（或客户端接收）响应数据包（ALT + F4）。我想要一些帮助。我将在两个项目的源代码下面进行copypaste。 客户端：
public class StateObject
{
public Socket skt = null;
public const int BufferSize = 256;
public byte[] buffer = new byte[BufferSize];
public StringBuilder sb = new StringBuilder();
}
public class AsynchronousClient
{
private const int port = 11000;
private static ManualResetEvent connectDone =
new ManualResetEvent(false);
private static ManualResetEvent sendDone =
new ManualResetEvent(false);
private static ManualResetEvent receiveDone =
new ManualResetEvent(false);
private static String response = String.Empty;
public static string command;
public static Socket client;
public static void StartClient()
{
try
{
IPHostEntry ipHostInfo = Dns.GetHostEntry(IPAddress.Parse("127.0.0.1"));
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint remoteEP = new IPEndPoint(IPAddress.Parse("127.0.0.1"), port);
client = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
client.BeginConnect(remoteEP,
new AsyncCallback(ConnectCallback), client);
connectDone.WaitOne();
while (true)
{
command = Console.ReadLine();
if (command == "exit")
{
Console.WriteLine("Terminating...");
client.Shutdown(SocketShutdown.Both);
client.Close();
Environment.Exit(0);
}
else
{
Send(client, command + "<EOF>");
sendDone.WaitOne();
Receive(client);
receiveDone.WaitOne();
Console.WriteLine("Response received : {0}", ProcessResponse(response));
client.Shutdown(SocketShutdown.Both);
client.Close();
}
//Console.CancelKeyPress += (sender, e) =>
//{
// Console.WriteLine("Terminating...");
// client.Shutdown(SocketShutdown.Both);
// client.Close();
// Environment.Exit(0);
//};
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
static public string ProcessResponse(string pkt)
{
string response = null;
response = pkt.Replace("<EOF>","");
return response;
}
private static void ConnectCallback(IAsyncResult ar)
{
try
{
Socket client = (Socket)ar.AsyncState;
client.EndConnect(ar);
Console.WriteLine("Socket connected to {0}",
client.RemoteEndPoint.ToString());
connectDone.Set();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void Receive(Socket client)
{
try
{
StateObject state = new StateObject();
state.skt = client;
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
{
StateObject state = (StateObject)ar.AsyncState;
Socket client = state.skt;
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0)
{
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReceiveCallback), state);
}
else
{
if (state.sb.Length > 1)
{
response = state.sb.ToString();
}
receiveDone.Set();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
private static void Send(Socket client, String data)
{
byte[] byteData = Encoding.ASCII.GetBytes(data);
client.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), client);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
Socket client = (Socket)ar.AsyncState;
int bytesSent = client.EndSend(ar);
Console.WriteLine("Sent {0} bytes to server.", bytesSent);
sendDone.Set();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
public static int Main(String[] args)
{
StartClient();
return 0;
}
服务器：
public class Program
{
public class StateObject
{
public Socket skt = null;
public const int buffersize = 1024;
public byte[] buffer = new byte[buffersize];
public StringBuilder sb = new StringBuilder();
}
public class AsynchronousSocketListener
{
public static ManualResetEvent allDone = new ManualResetEvent(false);
public AsynchronousSocketListener() { }
public static Socket handler;
public static void StartListening()
{
byte[] bytes = new Byte[1024];
IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
IPAddress ipAddress = ipHostInfo.AddressList[0];
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 11000);
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
while (true)
{
allDone.Reset();
Console.WriteLine("Waiting for a connection...");
listener.BeginAccept(
new AsyncCallback(AcceptCallback),
listener);
allDone.WaitOne();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
public static void AcceptCallback(IAsyncResult ar)
{
allDone.Set();
Socket listener = (Socket)ar.AsyncState;
Socket handler = listener.EndAccept(ar);
StateObject state = new StateObject();
state.skt = handler;
handler.BeginReceive(state.buffer, 0, StateObject.buffersize, 0, new AsyncCallback(ReadCallback), state);
}
public static void ReadCallback(IAsyncResult ar)
{
String content = String.Empty;
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.skt;
int bytesRead = handler.EndReceive(ar);
if (bytesRead > 0)
{
state.sb.Append(Encoding.ASCII.GetString(
state.buffer, 0, bytesRead));
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
Console.WriteLine("Read {0} bytes from socket. \n Data : {1}", content.Length, ProcessResponse(content));
Send(handler, content);
}
else
{
handler.BeginReceive(state.buffer, 0, StateObject.buffersize, 0,
new AsyncCallback(ReadCallback), state);
}
}
}
private static void Send(Socket handler, String data)
{
byte[] byteData = Encoding.ASCII.GetBytes(data);
handler.BeginSend(byteData, 0, byteData.Length, 0, new AsyncCallback(SendCallback), handler);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
handler = (Socket)ar.AsyncState;
int bytesSent = handler.EndSend(ar);
Console.WriteLine("Sent {0} bytes to client.", bytesSent);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
static public string ProcessResponse(String pkt)
{
string response = null;
response = pkt.Replace("<EOF>", "");
return response;
}
}
public static void Main(string[] args)
{
AsynchronousSocketListener.StartListening();
}
}
答案 0 :(得分：1)
在客户端接收回调：
private static void ReceiveCallback(IAsyncResult ar)
{
try
{
StateObject state = (StateObject)ar.AsyncState;
Socket client = state.skt;
int bytesRead = client.EndReceive(ar);
if (bytesRead > 0)
{
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
client.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReceiveCallback), state);
}
else
{
if (state.sb.Length > 1)
{
response = state.sb.ToString();
}
receiveDone.Set();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
除非显式关闭套接字（或连接中存在某种其他错误），否则不会下拉到else块。因此，receiveDone永远不会被设置，并且您的主循环只是等待“响应”。
如果您想在处理“完整消息”时处理它，请在将当前字符串附加到缓冲区后检查<EOF>值，如下所示：
if (bytesRead > 0)
{
state.sb.Append(Encoding.ASCII.GetString(state.buffer, 0, bytesRead));
// it's not a "response" unless it's terminated with "<EOF>" right?
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);
}
}
else
{
if (state.sb.Length > 1)
{
response = state.sb.ToString(); // this is a partial response, not terminated with "<EOF>"
}
receiveDone.Set();
}
请注意，正在使用的响应机制非常有限，因为同时进入的多条消息都会失败，如：Hello<EOF> World!<EOF>它会将这两条消息视为一条长消息。 （我意识到你的例子只发送一条“消息”。）
除了“内容”消息之外，您几乎肯定必须在任何发送“控制”消息的真实应用程序中处理该场景。要处理你使用IndexOf（）查找<EOF>并提取文本到那一点并处理“完成消息”。之后，只要仍然找到<EOF>来处理其他待处理消息，您就会继续循环。您还必须从StringBuilder中删除那些已处理的完整消息，使<EOF>之后的任何剩余值保留在原位，以便当部分消息进入时，新数据可以附加到现有数据。这是因为您的数据在发送时也可以被分割，导致收到多个“数据块”的数据，即使它在发送时逻辑上是一个“完整的消息”。因此，使用Complete Message<EOF>的一次发送可能会导致一个或多个收到，例如Comp后跟lete Message<EOF>。您的代码必须能够处理TCP通信的这些现实......