用来一次TCP

今天把原来用UDP做的数据传输模块改成了用TCP做。TCP这东西我已经很久没接触了，今天用起来还是有点生疏的。与UDP不同的是，TCP的服务器端需要有一个监听和接收来自客户端的连接请求，而客户端需要连接服务器端。也就是所说的三次握手吧。

因为在服务器端进行监听的时候，服务器上不能进行其他操作，因此我专门建了一个线程用于监听和接收数据。而本来想要建立的异步套接字，通过这个方法来实现异步通信，这下有了一个新的线程就不用了。这次我用了一个循环嵌套，也就是两个while(true)函数，一个用于初始发送数据，一个用于下一步接收查询。

具体代码如下：

DWORD WINAPI CBookMangageSystemDlg::ListenProc( LPVOID lpParameter // thread data ){WSABUF* pwsabuf = new WSABUF[3];CString strSend0,strSend1,strSend2;DWORD dwSend;int i = 0;SOCKET sock = ((RECVPARAM*)lpParameter)->sock;HWND hwnd= ((RECVPARAM*)lpParameter)->hwnd;SOCKET sockSend = ((RECVPARAM*)lpParameter)->sockSend;_RecordsetPtr Recordset = ((RECVPARAM*)lpParameter)->Recordset;_ConnectionPtr Connection = ((RECVPARAM*)lpParameter)->Connection;while(TRUE){if(SOCKET_ERROR == listen(sock,5)){AfxMessageBox("监听发生错误!");return 0;}int len = sizeof(SOCKADDR);SOCKADDR_IN addrFrom;if(INVALID_SOCKET == (sockSend = accept(sock,(SOCKADDR*)&addrFrom,&len))){AfxMessageBox("等待请求失败!");return 0;}/*if(SOCKET_ERROR == WSAAsyncSelect(sockSend,hwnd,UM_SOCK,FD_READ)){AfxMessageBox("创建网络读取事件失败");return 0;}*/if(Recordset->State)Recordset->Close();Recordset->Open("select * from bookinfo",_variant_t((IDispatch *)Connection,true),adOpenStatic,adLockOptimistic,adCmdText);_variant_t vbookid,vbookname,vbooknum;while(!Recordset->adoEOF){vbookid = Recordset->GetCollect("bookid");vbookname = Recordset->GetCollect("bookname");vbooknum = Recordset->GetCollect("booknum");strSend0 = (LPCTSTR)(_bstr_t)vbookid;pwsabuf[0].buf = strSend0.GetBuffer(strSend0.GetLength());pwsabuf[0].len = 100;strSend1 = (LPCTSTR)(_bstr_t)vbookname;pwsabuf[1].buf = strSend1.GetBuffer(strSend1.GetLength());pwsabuf[1].len = 200;strSend2 = (LPCTSTR)(_bstr_t)vbooknum;pwsabuf[2].buf = strSend2.GetBuffer(strSend2.GetLength());pwsabuf[2].len = 100;if(SOCKET_ERROR == WSASend(sockSend,pwsabuf,3,&dwSend,0,NULL,NULL)){AfxMessageBox("发送失败！");return 0;}Recordset ->MoveNext();}while(TRUE){WSABUF wsabuf;wsabuf.buf = new char[200];wsabuf.len = 200;DWORD dwRecv;DWORD dwFlag = 0;CString str = "select * from bookinfo where bookname = ";if(SOCKET_ERROR == WSARecv(sockSend,&wsabuf,1,&dwRecv,&dwFlag,NULL,NULL)){AfxMessageBox("接收失败！");break;}str += "'";str += wsabuf.buf;str += "'";if(Recordset->State)Recordset->Close();Recordset->Open(_variant_t(str),_variant_t((IDispatch *)Connection,true),adOpenStatic,adLockOptimistic,adCmdText);_variant_t vbookid,vbookname,vbooknum;while(!Recordset->adoEOF){vbookid = Recordset->GetCollect("bookid");vbookname = Recordset->GetCollect("bookname");vbooknum = Recordset->GetCollect("booknum");strSend0 = (LPCTSTR)(_bstr_t)vbookid;pwsabuf[0].buf = strSend0.GetBuffer(strSend0.GetLength());pwsabuf[0].len = 100;strSend1 = (LPCTSTR)(_bstr_t)vbookname;pwsabuf[1].buf = strSend1.GetBuffer(strSend1.GetLength());pwsabuf[1].len = 200;strSend2 = (LPCTSTR)(_bstr_t)vbooknum;pwsabuf[2].buf = strSend2.GetBuffer(strSend2.GetLength());pwsabuf[2].len = 100;if(SOCKET_ERROR == WSASend(sockSend,pwsabuf,3,&dwSend,0,NULL,NULL)){AfxMessageBox("发送失败！");break;}Recordset ->MoveNext();}}}return 1;}

继续努力吧。