我正在尝试使用c＃开发服务器/客户端异步套接字。我已按照MSDN链接的指南进行操作。在我的情况下，套接字服务器监听特定端点，许多客户端可以一次连接到服务器，客户端可以与服务器通信，服务器可以与客户端通信。假设客户端1和客户端2与服务器连接，客户端1可以向服务器发送消息，服务器可以发送给客户端1，同样适用于客户端2的情况。现在我希望客户端能够通过服务器相互通信。例如，客户端2想要与客户端1通信，因为客户端2将向服务器发送消息（此消息将包含一些预设字符;），然后服务器将从客户端2接收文本并将获取客户端1的处理程序并发送这个消息发送到客户端1，客户端1将响应服务器，现在我想将客户端1的响应发送给客户端2，但我不知道如何做到这一点，因为客户端1通过自己的处理程序与服务器进行通信，我很震惊，帮助将受到高度赞赏！ 我的代码如下：
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Net;
using System.Net.Sockets;
namespace SocketServer
{
// 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 int clientNumber;
}
public class AsyncSocketServer
{
public static ManualResetEvent allDone = new ManualResetEvent(false);
public static Dictionary<int, StateObject> Clients = new Dictionary<int, StateObject>();
public static int connectedClient = 0;
public AsyncSocketServer()
{
}
public static void startListening() {
Byte[] bytes = new Byte[1024];
int Port = 1122;
IPAddress IP = IPAddress.Parse("127.0.0.1");
IPEndPoint EP = new IPEndPoint(IP, Port);
Socket listner = new Socket(IP.AddressFamily, SocketType.Stream, ProtocolType.Tcp);
try
{
listner.Bind(EP);
listner.Listen(100);
while (true)
{
allDone.Reset();
Console.WriteLine("Waiting for the Connection......");
listner.BeginAccept(new AsyncCallback(AcceptCallBack), listner);
allDone.WaitOne();
}
}
catch(Exception e)
{
Console.WriteLine("Exception Occured ! in start listening method "+e.ToString());
}
Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}
public static void AcceptCallBack(IAsyncResult ar)
{
connectedClient++;
Console.WriteLine("client number " + connectedClient);
allDone.Set();
Socket listner = (Socket) ar.AsyncState;
Socket handler = listner.EndAccept(ar);
StateObject state = new StateObject();
state.clientNumber = connectedClient;
Clients.Add(connectedClient, state);
Console.WriteLine("total clients {0}",Clients.Count());
state.workSocket = handler;
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize,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.
try {
StateObject state = (StateObject) ar.AsyncState;
state.sb.Clear();
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.Substring(0, 3) == "cmd") {
foreach (StateObject Client in Clients.Values) {
if (Client.clientNumber == 1) {
Console.WriteLine("value is "+Client.clientNumber);
if (isClientConnected(Client.workSocket)){
Send(Client.workSocket, "did you receive my message");
//now client number 1 will response through its own handler, but i want to get response of
//client number 1 and return this response to client number 2
}
else {
string responsemsg = "client number " + Client.clientNumber + " is disconnected !";
Console.WriteLine(responsemsg);
Send(handler,responsemsg);
}
}
}
}
Console.WriteLine("Read {0} bytes from client {1} socket. \n Data : {2}",
content.Length, state.clientNumber,content);
// Echo the data back to the client.
if (isClientConnected(handler))
{
Send(handler, content);
}
handler.BeginReceive(state.buffer, 0, StateObject.BufferSize, 0, new AsyncCallback(ReadCallBack), state);
}
}
catch (SocketException e)
{
//once if any client disconnected then control will come into this block
Console.WriteLine("Socket Exception Occured in Read Call Back : " + e.Message.ToString());
}
catch (Exception e)
{
//once if any client disconnected then control will come into this block
Console.WriteLine("Exception Occured in Read Call Back : " + e.Message.ToString());
}
}
private static void Send(Socket handler, 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.
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();
}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}
}
public static bool isClientConnected(Socket handler){
return handler.Connected;
}
public static int Main(string[] args)
{
startListening();
return 0;
}
}
}
答案 0 :(得分：2)
对于任何基于套接字的复杂应用程序，我建议使用像DotNetty这样的套接字库来抽象传输层，并让您专注于应用程序逻辑。查看他们的SecureChat example，它可能与您尝试实现的非常类似。
我将一个DotNetty服务器的快速示例放在一起，允许您通过让客户端向服务器注册，然后让服务器在客户端之间路由消息来在客户端之间发送命令。
<div class="btn-file">
<input type="file" id="FileUpload1" class="" disabled>
<label for="FileUpload1" class="custom-file-upload">
<i class="fa fa-upload"></i> Upload Logo
</label>
</div>
答案 1 :(得分：0)
我也尝试基于MSDN的相同代码进行相同的操作 可能的解决方案是使用套接字列表：
List<Socket> clients = new List<Socket>();
然后，当客户端连接时，将客户端添加到列表中：
public 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);
clients.Add(handler);
...
}
您必须知道所连接的每个客户端的ID（句柄），然后才能向特定客户端发送一些消息：
public void SendToOne(string id,string message)
{
foreach (Socket s in clients)
{
if (s.Handle.ToString() == id)
{
Send(s, message);
}
}
}