我正在尝试创建异步服务器/客户端聊天程序。虽然我已经把它弄得很多，但我遇到了障碍。当客户端向服务器发送数据包时，它会被正确读取并进一步回送给该客户端而没有任何问题。如果连接了另一个客户端，它将立即收到该数据包......但它可能需要多次发送呼叫。另一个问题是尽管我付出了最大的努力，StateObject缓冲区（至少那是我认为的那样）并没有被清除。因此产生的结果非常不稳定和奇怪。任何方向都会非常有用！
Server.cs
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
using System.Collections.Generic;
namespace Async_Server
{
// State object for reading client data asynchronously
public class StateObject
{
// Client socket.
public Socket workSocket = null;
// Size of receive buffer.
public const int BufferSize = 1024;
// Receive buffer.
public byte[] buffer = new byte[BufferSize];
// Received data string.
public StringBuilder sb = new StringBuilder();
}
public class StatesHandler
{
public List<StateObject> States = new List<StateObject>();
public int Counter = 0;
}
public class AsynchronousSocketListener
{
public static Async_Server.StatesHandler stateshandler = new StatesHandler();
// Thread signal.
public static ManualResetEvent allDone = new ManualResetEvent(false);
public AsynchronousSocketListener()
{
}
public static void StartListening()
{
// Data buffer for incoming data.
byte[] bytes = new Byte[1024];
// Establish the local endpoint for the socket.
// The DNS name of the computer
// running the listener is "host.contoso.com".
//IPHostEntry ipHostInfo = Dns.Resolve(Dns.GetHostName());
//IPAddress ipAddress = ipHostInfo.AddressList[0];
//IPHostEntry ipHostInfo = Dns.GetHostByName(Dns.GetHostName());
//IPAddress ipAddress = ipHostInfo.AddressList[0];
//IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 3000);
IPAddress ipAddress = IPAddress.Loopback;
IPEndPoint localEndPoint = new IPEndPoint(ipAddress, 3000);
// Create a TCP/IP socket.
Socket listener = new Socket(AddressFamily.InterNetwork,
SocketType.Stream, ProtocolType.Tcp);
// Bind the socket to the local endpoint and listen for incoming connections.
try
{
listener.Bind(localEndPoint);
listener.Listen(100);
Console.WriteLine("Waiting for a connection @ " + ipAddress.ToString());
while (true)
{
// Set the event to nonsignaled state.
allDone.Reset();
// Start an asynchronous socket to listen for connections.
listener.BeginAccept(
new AsyncCallback(AcceptCallback),
listener);
// Wait until a connection is made before continuing.
allDone.WaitOne();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
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.
StateObject state = new StateObject();
//Store state instance in stateshandler
stateshandler.States.Add(state);
stateshandler.Counter++;
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
listener.BeginAccept(
new AsyncCallback(AcceptCallback),
listener);
Console.WriteLine("Connection accepted from: " + handler.RemoteEndPoint.ToString());
}
public static void ReadCallback(IAsyncResult ar)
{
try
{
String content = String.Empty;
// Retrieve the state object and the handler socket
// from the asynchronous state object.
if ((StateObject)ar.AsyncState != null)
{
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Read data from the client socket.
int bytesRead = handler.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));
// Check for end-of-file tag. If it is not there, read
// more data.
content = state.sb.ToString();
if (content.IndexOf("<EOF>") > -1)
{
// All the data has been read from the
// client. Display it on the console.
Console.WriteLine("Read {0} bytes from socket. \n Data : {1}",
content.Length, content);
// Echo the data back to the client.
Send(ar, content);
content = null;
}
else
{
// Not all data received. Get more.
try
{
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
catch (Exception e)
{
Console.WriteLine(e);
Console.Read();
}
}
}
else
{
Console.WriteLine("RAWR");
Console.Read();
}
}
}
catch (Exception e)
{
Console.WriteLine("Connection terminated from: ", e);
}
}
private static void Send(IAsyncResult ar, String data)
{
/*
for (int i = 0; i < stateshandler.Counter; i++)
{
StateObject state = stateshandler.States[i];
Socket handler = state.workSocket;
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,
new AsyncCallback(SendCallback), state);
}
*/
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
// Begin sending the data to the remote device.
handler.BeginSend(byteData, 0, byteData.Length, 0,
new AsyncCallback(SendCallback), state);
}
private static void SendCallback(IAsyncResult ar)
{
try
{
// Retrieve the socket from the state object.
StateObject state = (StateObject)ar.AsyncState;
Socket handler = state.workSocket;
// Complete sending the data to the remote device.
int bytesSent = handler.EndSend(ar);
Console.WriteLine("Sent {0} bytes to client.", bytesSent);
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0,
new AsyncCallback(ReadCallback), state);
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
}
public static int Main(String[] args)
{
try
{
StartListening();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
Console.Read();
return 0;
}
}
}
Client.cs
using System;
using System.Net;
using System.Net.Sockets;
using System.Text;
using System.Threading;
public 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();
}
public class Program
{
public static ManualResetEvent connectDone = new ManualResetEvent(false);
public static ManualResetEvent sendDone = new ManualResetEvent(false);
public static ManualResetEvent receiveDone = new ManualResetEvent(false);
public static void Connect(EndPoint remoteEP, Socket client)
{
client.BeginConnect(remoteEP,
new AsyncCallback(ConnectCallback), client);
connectDone.WaitOne();
}
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 Send(Socket client, String data)
{
// Convert the string data to byte data using ASCII encoding.
byte[] byteData = Encoding.ASCII.GetBytes(data);
// Begin sending the data to the remote device.
client.BeginSend(byteData, 0, byteData.Length, SocketFlags.None,
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());
}
}
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));
Console.WriteLine(state.sb.ToString());
// Get the rest of the data.
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)
{
string response = state.sb.ToString();
Console.WriteLine(response);
}
// Signal that all bytes have been received.
receiveDone.Set();
}
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
static void Main(string[] args)
{
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), 3000);
Socket sock = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
Connect(localEndPoint, sock);
string packet;
while (true)
{
packet = Console.ReadLine();
packet += "<EOF>";
Send(sock, packet);
Receive(sock);
connectDone.WaitOne();
packet = null;
}
}
}