我已经设法将客户端连接到服务器并在它们之间发送数据，但我似乎无法让它们聊天。条件:- 服务器必须打印出对话，以及两个客户端之间的对话。 这是我的服务器代码

#include <windows.h> 
#include <stdio.h> 
#include <tchar.h>
#include <strsafe.h>

#define BUFSIZE 512

DWORD WINAPI InstanceThread(LPVOID); 
VOID GetAnswerToRequest(LPTSTR, LPTSTR, LPDWORD); 

int _tmain(VOID) 
{ 
   BOOL   fConnected = FALSE; 
   DWORD  dwThreadId = 0; 
   HANDLE hPipe = INVALID_HANDLE_VALUE, hThread = NULL; 
   LPTSTR lpszPipename = TEXT("\\\\.\\pipe\\mynamedpipe"); 

// The main loop creates an instance of the named pipe and 
// then waits for a client to connect to it.

   for (;;) 
   { 
      _tprintf( TEXT("\nPipe Server: Main thread awaiting client connection on %s\n"), lpszPipename);
      hPipe = CreateNamedPipe( 
          lpszPipename,             // pipe name 
          PIPE_ACCESS_DUPLEX,       // read/write access 
          PIPE_TYPE_MESSAGE |       // message type pipe 
          PIPE_READMODE_MESSAGE |   // message-read mode 
          PIPE_WAIT,                // blocking mode 
          PIPE_UNLIMITED_INSTANCES, // max. instances  
          BUFSIZE,                  // output buffer size 
          BUFSIZE,                  // input buffer size 
          0,                        // client time-out 
          NULL);                    // default security attribute 

      if (hPipe == INVALID_HANDLE_VALUE) 
      {
          _tprintf(TEXT("CreateNamedPipe failed, GLE=%d.\n"), GetLastError()); 
          return -1;
      }

      // Wait for the client to connect; if it succeeds, 
      // the function returns a nonzero value. If the function
      // returns zero, GetLastError returns ERROR_PIPE_CONNECTED. 

      fConnected = ConnectNamedPipe(hPipe, NULL) ? 
         TRUE : (GetLastError() == ERROR_PIPE_CONNECTED); 

      if (fConnected) 
      { 
         printf("Client connected, creating a processing thread.\n"); 

         // Create a thread for this client. 
         hThread = CreateThread( 
            NULL,              // no security attribute 
            0,                 // default stack size 
            InstanceThread,    // thread proc
            (LPVOID) hPipe,    // thread parameter 
            0,                 // not suspended 
            &dwThreadId);      // returns thread ID 

         if (hThread == NULL) 
         {
            _tprintf(TEXT("CreateThread failed, GLE=%d.\n"), GetLastError()); 
            return -1;
         }
         else CloseHandle(hThread); 
       } 
      else 
        // The client could not connect, so close the pipe. 
         CloseHandle(hPipe); 
   } 

   return 0; 
} 

DWORD WINAPI InstanceThread(LPVOID lpvParam)
// This routine is a thread processing function to read from and reply to a client

{ 
   HANDLE hHeap      = GetProcessHeap();
   TCHAR* pchRequest = (TCHAR*)HeapAlloc(hHeap, 0, BUFSIZE*sizeof(TCHAR));
   TCHAR* pchReply   = (TCHAR*)HeapAlloc(hHeap, 0, BUFSIZE*sizeof(TCHAR));

   DWORD cbBytesRead = 0, cbReplyBytes = 0, cbWritten = 0; 
   BOOL fSuccess = FALSE;
   HANDLE hPipe  = NULL;

   // Do some extra error checking since the app will keep running even if this
   // thread fails.

   if (lpvParam == NULL)
   {
       printf( "\nERROR - Pipe Server Failure:\n");
       printf( "   InstanceThread got an unexpected NULL value in lpvParam.\n");
       printf( "   InstanceThread exitting.\n");
       if (pchReply != NULL) HeapFree(hHeap, 0, pchReply);
       if (pchRequest != NULL) HeapFree(hHeap, 0, pchRequest);
       return (DWORD)-1;
   }

   if (pchRequest == NULL)
   {
       printf( "\nERROR - Pipe Server Failure:\n");
       printf( "   InstanceThread got an unexpected NULL heap allocation.\n");
       printf( "   InstanceThread exitting.\n");
       if (pchReply != NULL) HeapFree(hHeap, 0, pchReply);
       return (DWORD)-1;
   }

   if (pchReply == NULL)
   {
       printf( "\nERROR - Pipe Server Failure:\n");
       printf( "   InstanceThread got an unexpected NULL heap allocation.\n");
       printf( "   InstanceThread exitting.\n");
       if (pchRequest != NULL) HeapFree(hHeap, 0, pchRequest);
       return (DWORD)-1;
   }

   // Print verbose messages. In production code, this should be for debugging only.
   printf("InstanceThread created, receiving and processing messages.\n");

// The thread's parameter is a handle to a pipe object instance. 

   hPipe = (HANDLE) lpvParam; 

// Loop until done reading
   while (1) 
   { 
   // Read client requests from the pipe. This simplistic code only allows messages
   // up to BUFSIZE characters in length.
      fSuccess = ReadFile( 
         hPipe,        // handle to pipe 
         pchRequest,    // buffer to receive data 
         BUFSIZE*sizeof(TCHAR), // size of buffer 
         &cbBytesRead, // number of bytes read 
         NULL);        // not overlapped I/O 

      if (!fSuccess || cbBytesRead == 0)
      {   
          if (GetLastError() == ERROR_BROKEN_PIPE)
          {
              _tprintf(TEXT("InstanceThread: client disconnected.\n"), GetLastError()); 
          }
          else
          {
              _tprintf(TEXT("InstanceThread ReadFile failed, GLE=%d.\n"), GetLastError()); 
          }
          break;
      }

   // Process the incoming message.
      GetAnswerToRequest(pchRequest, pchReply, &cbReplyBytes); 

   // Write the reply to the pipe. 
      fSuccess = WriteFile( 
         hPipe,        // handle to pipe 
         pchReply,     // buffer to write from 
         cbReplyBytes, // number of bytes to write 
         &cbWritten,   // number of bytes written 
         NULL);        // not overlapped I/O 

      if (!fSuccess || cbReplyBytes != cbWritten)
      {   
          _tprintf(TEXT("InstanceThread WriteFile failed, GLE=%d.\n"), GetLastError()); 
          break;
      }
  }

// Flush the pipe to allow the client to read the pipe's contents 
// before disconnecting. Then disconnect the pipe, and close the 
// handle to this pipe instance. 

   FlushFileBuffers(hPipe); 
   DisconnectNamedPipe(hPipe); 
   CloseHandle(hPipe); 

   HeapFree(hHeap, 0, pchRequest);
   HeapFree(hHeap, 0, pchReply);

   printf("InstanceThread exitting.\n");
   return 1;
}

VOID GetAnswerToRequest( LPTSTR pchRequest, 
                         LPTSTR pchReply, 
                         LPDWORD pchBytes )
// This routine is a simple function to print the client request to the console
// and populate the reply buffer with a default data string. This is where you
// would put the actual client request processing code that runs in the context
// of an instance thread.
{
    _tprintf( TEXT("Client Request String:\"%s\"\n"), pchRequest );

    // Check the outgoing message to make sure it's not too long for the buffer.
    if (FAILED(StringCchCopy( pchReply, BUFSIZE, TEXT("default answer from server") )))
    {
        *pchBytes = 0;
        pchReply[0] = 0;
        printf("StringCchCopy failed, no outgoing message.\n");
        return;
    }
    *pchBytes = (lstrlen(pchReply)+1)*sizeof(TCHAR);
}

这是我的客户端代码

#include <windows.h> 
#include <stdio.h>
#include <conio.h>
#include <tchar.h>

#define BUFSIZE 512

int _tmain(int argc, TCHAR *argv[]) 
{ 
   HANDLE hPipe; 
   LPTSTR lpvMessage=TEXT("Default message from client."); 
   TCHAR  chBuf[BUFSIZE]; 
   BOOL   fSuccess = FALSE; 
   DWORD  cbRead, cbToWrite, cbWritten, dwMode; 
   LPTSTR lpszPipename = TEXT("\\\\.\\pipe\\mynamedpipe"); 

   if( argc > 1 )
      lpvMessage = argv[1];

// Try to open a named pipe; wait for it, if necessary. 

   while (1) 
   { 
      hPipe = CreateFile( 
         lpszPipename,   // pipe name 
         GENERIC_READ |  // read and write access 
         GENERIC_WRITE, 
         0,              // no sharing 
         NULL,           // default security attributes
         OPEN_EXISTING,  // opens existing pipe 
         0,              // default attributes 
         NULL);          // no template file 

   // Break if the pipe handle is valid. 

      if (hPipe != INVALID_HANDLE_VALUE) 
         break; 

      // Exit if an error other than ERROR_PIPE_BUSY occurs. 

      if (GetLastError() != ERROR_PIPE_BUSY) 
      {
         _tprintf( TEXT("Could not open pipe. GLE=%d\n"), GetLastError() ); 
         return -1;
      }

      // All pipe instances are busy, so wait for 20 seconds. 

      if ( ! WaitNamedPipe(lpszPipename, 20000)) 
      { 
         printf("Could not open pipe: 20 second wait timed out."); 
         return -1;
      } 
   } 

// The pipe connected; change to message-read mode. 

   dwMode = PIPE_READMODE_MESSAGE; 
   fSuccess = SetNamedPipeHandleState( 
      hPipe,    // pipe handle 
      &dwMode,  // new pipe mode 
      NULL,     // don't set maximum bytes 
      NULL);    // don't set maximum time 
   if ( ! fSuccess) 
   {
      _tprintf( TEXT("SetNamedPipeHandleState failed. GLE=%d\n"), GetLastError() ); 
      return -1;
   }

// Send a message to the pipe server. 

   cbToWrite = (lstrlen(lpvMessage)+1)*sizeof(TCHAR);
   _tprintf( TEXT("Sending %d byte message: \"%s\"\n"), cbToWrite, lpvMessage); 

   fSuccess = WriteFile( 
      hPipe,                  // pipe handle 
      lpvMessage,             // message 
      cbToWrite,              // message length 
      &cbWritten,             // bytes written 
      NULL);                  // not overlapped 

   if ( ! fSuccess) 
   {
      _tprintf( TEXT("WriteFile to pipe failed. GLE=%d\n"), GetLastError() ); 
      return -1;
   }

   printf("\nMessage sent to server, receiving reply as follows:\n");

   do 
   { 
   // Read from the pipe. 

      fSuccess = ReadFile( 
         hPipe,    // pipe handle 
         chBuf,    // buffer to receive reply 
         BUFSIZE*sizeof(TCHAR),  // size of buffer 
         &cbRead,  // number of bytes read 
         NULL);    // not overlapped 

      if ( ! fSuccess && GetLastError() != ERROR_MORE_DATA )
         break; 

      _tprintf( TEXT("\"%s\"\n"), chBuf ); 
   } while ( ! fSuccess);  // repeat loop if ERROR_MORE_DATA 

   if ( ! fSuccess)
   {
      _tprintf( TEXT("ReadFile from pipe failed. GLE=%d\n"), GetLastError() );
      return -1;
   }

   printf("\n<End of message, press ENTER to terminate connection and exit>");
   _getch();

   CloseHandle(hPipe); 

   return 0; 
}

最佳答案

为了映射对话的参与者，一种方法是使用地址到别名的映射。你可以使用 std::map<std::string, std::string>为了那个原因。为了填充 map ，您需要先提供身份信息。

另一种方法是在每条消息中包含别名。为此，您需要定义自己的消息协议(protocol)。例如，您可以将其基于 xml(从而利用现成的 xml 库):

<msg>
    <src>Dave</src>
    <dest>Steve</dest>
    <payload>
        <b>HI!</b>How are <u>you</u>
    </payload>
</msg>

关于c++ - 使用命名管道的客户端服务器聊天，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/8877120/