利用CAsyncSocket类实现Socket编程

1、利用CAsyncSocket类实现Socket编程更新时间：2007-10-20作者：佚名来源：常州vc网本文关键词：CAsyncSocket类socket编程随着计算机网络化的深入，计算机网络编程在程序设计的过程中变得日益重要。许多文章都曾经介绍过用VC+进行Socket编程的方法。但由于都是直接利用动态连接库wsock32.dll进行操作，实现比较繁琐。其实，VC+的MFC类库中提供了CAsyncSocket这样一个套接字类，用它来实现Socket编程，是非常方便的。客户端创建一个DialogBased项目：CSockClient。设计一对话框，增力口ID_Connect(连接)、ID_S

2、end(发送)、ID_Exit(关闭)按钮，增加ListBox控件IDC_LISTMSG和Edit控件IDC_EDITMSG,并按下表在ClassWizard中为CCSockClientDlg类添加变量。ControlIDTypeMemberIDC_EDITMSGCEditm_MSGIDC_LISTMSGClistBoxm_MSGS在MySock.ccp中添加以下代码：#includeCSockClient.h#includeCSockClientDlg.h在MySock.h中添加以下代码：public:BOOLm_bConnected;UINTm_nLength;charm_szBuffer

3、4096;在MySock.ccp中重载各函数MySock:MySock()m_nLength=0;memset(m_szBuffer,0,sizeof(m_szBuffer);m_bConnected=FALSE;MySock:MySock()/关闭套接字if(m_hSocket!=INVALID_SOCKET)Close();voidMySock:OnReceive(intnErrorCode)m_nLength=Receive(m_szBuffer,sizeof(m_szBuffer),0);/下面两行代码用来获取对话框指针CCSockClientApp*pApp=(CCSockClien

4、tApp*)AfxGetApp();CCSockClientDlg*pDlg=(CCSockClientDlg*)pApp-m_pMainWnd;pDlg-m_MSGS.InsertString(0,m_szBuffer);memset(m_szBuffer,0,sizeof(m_szBuffer);CAsyncSocket:OnReceive(nErrorCode);voidMySock:OnSend(intnErrorCode)Send(m_szBuffer,m_nLength,0);m_nLength=0;memset(m_szBuffer,0,sizeof(m_szBuffer);/继

5、续提请一个读”的网络事件，接收Server消息AsyncSelect(FD_READ);CAsyncSocket:OnSend(nErrorCode);voidMySock:OnConnect(intnErrorCode)if(nErrorCode=0)m_bConnected=TRUE;CCSockClientApp*pApp=(CCSockClientApp*)AfxGetApp();CCSockClientDlg*pDlg=(CCSockClientDlg*)pApp-m_pMainWnd;memcpy(m_szBuffer,Connectedto,13);strncat(m_szBuf

6、fer,pDlg-m_szServerAdr,sizeof(pDlg-m_szServerAdr);pDlg-m_MSGS.InsertString(0,m_szBuffer);AsyncSelect(FD_READ);/提请一个读”的网络事件，准备接收CAsyncSocket:OnConnect(nErrorCode);建一对话框IDD_Addr,用来输入IP地址和Port;增加两个Edit控件：IDC_Addr、IDC_Port按下表在ClassWizard中为CAddrDlg类添加变量。ControlIDTypeMemberIDC_AddrCStringm_AddrIDC_PortInt

7、m_Port在CSockClientDlg.ccp中添加代码:#includeAddrDlg.hprotected:intTryCount;MySockm_clientSocket;UINTm_szPort;public:charm_szServerAdr256;双击IDD_CSOCKCLIENT_DIALOG对话框中的连接”按钮，添加以下代码:m_clientSocket.ShutDown(2);m_clientSocket.m_hSocket=INVALID_SOCKET;m_clientSocket.m_bConnected=FALSE;CAddrDlgm_Dlg;m_Dlg.m_Por

8、t=1088;/默认端口1088if(m_Dlg.DoModal()=IDOK&!m_Dlg.m_Add匚IsEmpty()memcpy(m_szServerAdr,m_Dlg.m_Addr,sizeof(m_szServerAdr);m_szPort=m_Dlg.m_Port;SetTimer(1,1000,NULL);/建立计时器，每1秒尝试连接一次TryCount=0;添加Windows消息WM_TIMER响应函数OnTimervoidCCSockClientDlg:OnTimer(UINTnIDEvent)(if(m_clientSocket.m_hSocket=INVALID_SOC

9、KET)(BOOLbFlag=m_clientSocket.Create(0,SOCK_STREAM,FD_CONNECT);if(!bFlag)(AfxMessageBox(SocketError!);m_clientSocket.Close();PostQuitMessage(O);return;m_clientSocket.Connect(m_szServerAdr,m_szPort);TryCount+;if(TryCount=10|m_clientSocket.m_bConnected)KillTimer(1);if(TryCount=10)AfxMessageBox(Connect

10、Failed!);return;CDialog:OnTimer(nIDEvent);双击IDD_CSOCKCLIENT_DIALOG对话框中的发送”按钮，添加以下代码:voidCCSockClientDlg:OnSend()(if(m_clientSocket.m_bConnected)(m_clientSocket.m_nLength=m_MSG.GetWindowText(m_clientSocket.m_szBuffer,sizeof(m_clientSocket.m_szBuffer);m_clientSocket.AsyncSelect(FD_WRITE);m_MSG.SetWind

11、owText();)voidCCSockClientDlg:OnExit()m_clientSocket.ShutDown(2);/关闭SocketEndDialog(0);运行此项目，连接时输入主机名或IP均可，CAsyncSocket类会自动处理服务端Server端的编程与Client端的类似，下面主要介绍他的Listen及Accept函数。建立一个CNewSocket类，重载CAsyncSocket类的OnReceive、OnSend函数，如何进行信息的显示和发送可以参考Client程序。本例中采用将收到信息原封不动发回的方法来实现Echo功能，代码如下：CNewSocket:OnRec

12、eive(intnErrorCOde)m_nLength=Receive(m_szBuffer,sizeof(m_szBuffer),0)；AsyncSelect(FD_WRITE);/直接转发消息CNewSocket:OnSend(intnErrorCode)建立一个CMyServerSocket类，重载CAsyncSocket类的OnAccept函数代码如下：在MyServerSocket.h中声明变量public:：CNewSocket*m_pSocket；voidCMyServerSocket:OnAccept(intnErrorCode)CNewSocket*pSocket=newC

13、NewSocket()；if(Accept(*pSocket)pSocket-AsyncSelect(FD_READ);m_pSocket=pSocket；elsedeletepSocket；为对话框添加一个侦听”按钮，添加如下代码:在CsockServerDlg.ccp中声明变量public:CMyServerSocketm_srvrSocket;voidCCSockServerDlg:OnListen()SOCK_STREAM , FD_ACCEPT);if(m_srvrSocket.m_hSocket=INVALID_SOCKETBOOLbFlag=m_srvrSocket.Create(UserPortif(!bFlag)AfxMessageBox(SocketError!”)；M_srvrSocket.Close()；PostQuitMessage(0)；Return；if(!m_srvrSocket。Listen(1)intnErrorCode=m_srvrSocket.GetLastErrorif(nError!=WSAEWOULDBLOCK)AfxMessageBox(SocketError!”)；M_srvrSocket.Close()；P