一个最简单的服务端和客户端(用CSocket)

功能：服务器端程序处于监听状态，等待客户端连接。客户端发来数据后，服务端回发一个消息，同时关闭连接！

源码下载

服务器(采用一个监听线程)核心代码：

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BOOL CListenThread::InitInstance()

{

//  if (!AfxSocketInit())

//  {

//      AfxMessageBox(IDP_SOCKETS_INIT_FAILED);

//      return FALSE;

//  }

    m_bListening = TRUE;            // 线程启动时默认处于监听状态

    while(1)

    {

        if(m_bListening)

        {

            StartListen();

        }

    }

 

    return TRUE;

}

 

int CListenThread::ExitInstance()

{

    StopListen();

 

    return CWinThread::ExitInstance();

}

 

BOOL CListenThread::StartListen()

{

    CString sResult;

    try

    {

        if(m_pListenSocket == NULL)

            m_pListenSocket = new CSocket;

        if(m_pListenSocket && m_pListenSocket->Create(m_nPort))      // Create()内部包含了Bind()

        {

            m_pListenSocket->Listen();

            m_pMainDlg->ShowInfo("启动监听成功");

            PostMessage(m_pMainDlg->GetSafeHwnd(), WM_ENABLE_LISTENING, 0, 0);

            while(1)

            {

                CSocket clientSocket;

                if(m_pListenSocket->Accept(clientSocket))

                {

                    char buffer[1024] = {0};

                    CString sText;

                    clientSocket.Receive(buffer, 1024);

                    sText = buffer;

                    m_pMainDlg->ShowInfo(sText);

 

                    CString s = "Thank you, JoeBlack";

                    clientSocket.Send(s, s.GetLength());

//                  send(clientSocket.m_hSocket, s, s.GetLength(), 0);      // 与上一句等效

 

                    if(sText == "close")            // stop listening

                    {

                        StopListen();

                        break;

                    }

                    else if(sText == "quit")        // post a message to let the main thread delete listen-thread

                    {

                        EndMyThread();

                        return TRUE;

                    }

                }

            }

            return TRUE;

        }

    }

    catch (CException* e)

    {

        char str[300] = {0};

        e->GetErrorMessage(str, 300);

        sResult.Format("启动监听失败，错误码：%d", str);

        m_pMainDlg->ShowInfo(sResult);

    }

    catch(...)

    {

        int err;

        err = WSAGetLastError();

        sResult.Format("启动监听失败，错误码：%d", err);

        m_pMainDlg->ShowInfo(sResult);

    }

    m_bListening = FALSE;

 

    return FALSE;

}

 

BOOL CListenThread::StopListen()                    // 停止服务器监听

{

    if(m_pListenSocket)

    {

        m_pListenSocket->Close();

        delete m_pListenSocket;

        m_pListenSocket = NULL;

        m_pMainDlg->ShowInfo("Stop listening successful");

        m_bListening = FALSE;

        m_pMainDlg->PostMessage(WM_ENABLE_LISTENING, 1, 0);  // 让“启动监听”按钮变为可用

    }

    return TRUE;

}

 

BOOL CListenThread::EndMyThread()                       // 关闭CSocket并退出本线程

{

    StopListen();

    m_pMainDlg->ShowInfo("Exit from Listen-Thread");

    PostMessage(m_pMainDlg->GetSafeHwnd(), WM_FREE_LISTENTHREAD, 0, 0);

 

    return TRUE;

}

服务端程序实现监听，当收到close或quit时，会停止监听，这时客户端即使发来数据，也不会被收到。服务器端点击窗口中的“开启监听”后，可以重新开启监听线程。

客户端程序(向server发送消息并接收返回值)：

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void CClientAppDlg::OnBtnSend()

{

    CSocket sendSocket;

    if(sendSocket.Create())

    {

        if(sendSocket.Connect("127.0.0.1", 5050))

        {

            UpdateData();

            sendSocket.Send(m_strEdit, m_strEdit.GetLength());

            Sleep(100);  // 等待服务器端数据返回

 

            char buf[1024] = {0};

            CString sResponse;

            while(sendSocket.Receive(buf, 1024))

            //while(recv(sendSocket, buf, 1024, 0))

            {

                sResponse += buf;

            }

 

            MessageBox(sResponse);

            sendSocket.Close();

        }

    }

}