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!
服务器(采用一个监听线程)核心代码:
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):
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(); } } }