自制即时通信系统：socket网络编程（5）
从本节开始，从IM的功能出发，以及代码展示来实现IM客户端：
从第一个用例开始：注册
注册按钮是放置在登陆界面上的，笔者的登陆界面展示如下：
单击注册按钮后，出现如下界面：
如图所示，登陆界面是程序的主对话框，客户端的注册框的任务是：
1)建立客户端与服务端链接//这一步在CRegister::OnInitDialog()中执行
2)填写注册信息
3)检查信息格式//此步以及后面的步骤在CRegister::OnOK()中执行
4)发送注册包
5)接受服务端的反馈包
8)断开与服务端的链接
根据上面的流程，当填好注册信息后，主要执行代码如下：
BOOL CRegister::OnInitDialog() {CDialog::OnInitDialog();// TODO: Add extra initialization here//设置默认性别((CButton *)GetDlgItem(IDC_RADIO3))->SetCheck(TRUE);//选上sex=0x04;//添加代码--〉向服务器申请登陆BYTE *pIP;//获取IP控件AddressCString strIP;DWORD dwIP;CWnd *pWnd=GetParent();((CLoggingDlg *)pWnd)->m_Address.GetAddress(dwIP);pIP = (unsigned char*)&dwIP;strIP.Format( "%u.%u.%u.%u ",*(pIP+3), *(pIP+2), *(pIP+1), *pIP);//链接extern CTCPSocket sock;if(sock.SetupTCPClientSocket(strIP, ((CLoggingDlg *)pWnd)->m_strPort)<0){::MessageBox(NULL,"socket() or connect() failed","system error",MB_OK|MB_ICONERROR);}else//链接成功{sock.rio_readinitb(sock.rio, sock.sock);}return TRUE; // return TRUE unless you set the focus to a control // EXCEPTION: OCX Property Pages should return FALSE}void CRegister::OnOK() {// 本地数据检验与处理UpdateData(TRUE);if(m_ByteAge>130)::MessageBox(NULL,"年龄范围在0-130之间","错误信息",MB_OK|MB_ICONERROR);if(m_strPass!=m_strRePass)::MessageBox(NULL,"两次密码输入不一致","错误信息",MB_OK|MB_ICONERROR);m_strName.TrimLeft();m_strName.TrimRight();//发送数据extern CTCPSocket sock;cln_register reg;reg.magic=0x54;reg.flags=0x02;sprintf(reg.name,"%s",m_strName);sprintf(reg.pass,"%s",m_strPass);sprintf(reg.city,"%s",m_strCity);reg.age=m_ByteAge;reg.sex=sex;sprintf(reg.info,"%s",m_strInfo);int num;if((num=sock.rio_writeline(sock.sock, ?, sizeof(reg), 0))<0)::MessageBox(NULL,"发送注册消息失败","system error",MB_OK|MB_ICONERROR);//接受数据char buf[88];int size=sock.rio_readlineb(sock.rio, buf, sizeof(buf));serv_register *serv_reg=(serv_register *)buf;if(serv_reg->magic==0x55 && serv_reg->flags==0x02){CString str="注册成功,id:";str += serv_reg->id;str += "密码：";str += serv_reg->pass;::MessageBox(NULL,str,"system error",MB_OK);closesocket(sock);//关闭TCP套接字CDialog::OnOK();}else{::MessageBox(NULL,"注册失败，请重新注册","system error",MB_OK|MB_ICONERROR);}}
以上就是注册用例了，可以看出明显的缺陷是：每次注册都会链接一次服务器，注册结束后直接回到登陆界面，关于注册失败也没有采取保留措施，导致用户友好性不是很好，不过这些都可以改善，读者有兴趣可以试一试；
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既然讲了注册，下面就将登陆一并讲了吧：
客户端的登陆任务步骤如下：
1)建立客户端与服务端链接
2)输入登录信息
3)本地校验输入信息格式错误
4）发送登录请求
5)接受服务端的反馈包
6）分析包：登陆成功或失败（成功则进入好友界面，接受好友信息）
根据上面的流程，当填好登陆信息后，主要执行代码如下：
BOOL CLoggingDlg::OnInitDialog() {CDialog::OnInitDialog();// TODO: Add extra initialization herem_ButtonCheckPort.SetCheck(BST_CHECKED);//默认自动获取portif(m_ButtonCheckPort.GetCheck()){m_EditPort.EnableWindow(FALSE);}m_ButtonIp.SetCheck(BST_CHECKED);//使用默认IPif(m_ButtonIp.GetCheck()){m_Address.EnableWindow(FALSE);}//设置IP默认值CString strIP = "127.0.0.1 ";DWORD dwIP = inet_addr(strIP);BYTE *pIP = (BYTE*)&dwIP;m_Address.SetAddress(*pIP, *(pIP+1), *(pIP+2), *(pIP+3));return TRUE; // return TRUE unless you set the focus to a control // EXCEPTION: OCX Property Pages should return FALSE}void CLoggingDlg::OnCheckPort() {// TODO: Add your control notification handler code hereif(m_ButtonCheckPort.GetCheck()){m_EditPort.EnableWindow(FALSE);}elsem_EditPort.EnableWindow(TRUE);}void CLoggingDlg::OnCheckIp() {// TODO: Add your control notification handler code hereif(m_ButtonIp.GetCheck()){m_Address.EnableWindow(FALSE);}elsem_Address.EnableWindow(TRUE);}void CLoggingDlg::OnOK() { // TODO: 本地校验 this->UpdateData(TRUE); if((strcmp(this->m_strUserId,"")==0) || (strcmp(this->m_strPassword ,"")==0)) { ::MessageBox(NULL,"用户名或口令不能为空！","错误信息",MB_OK|MB_ICONERROR); } else { this->UpdateData(TRUE); //添加代码--〉向服务器申请登陆 BYTE *pIP;//获取IP控件Address CString strIP; DWORD dwIP; m_Address.GetAddress(dwIP); pIP = (unsigned char*)&dwIP; strIP.Format( "%u.%u.%u.%u ",*(pIP+3), *(pIP+2), *(pIP+1), *pIP); //生成链接socket extern CTCPSocket sock; //extern rio_t rio; if(sock.SetupTCPClientSocket(strIP, m_strPort)<0) { ::MessageBox(NULL,"socket() or connect() failed","system error",MB_OK|MB_ICONERROR); } else//链接成功 { sock.rio_readinitb(sock.rio, sock.sock); cln_log log; log.magic=0x54; log.flags=0x01; sprintf(log.userid,"%s",m_strUserId); sprintf(log.password,"%s",m_strPassword); char buf[10]; memset(buf,'\0',sizeof(buf)); int num; if((num=sock.rio_writeline(sock.sock, &log, sizeof(log), 0))<=0) ::MessageBox(NULL,"rio_writen() failed","system error",MB_OK|MB_ICONERROR);
int size=sock.rio_readlineb(sock.rio, buf, sizeof(buf));
if(size>0) { header *servlog =(header *)buf; if((servlog->magic==0x55) && (servlog->flags==0x01)) //登录成功 CDialog::OnOK();//打开好友聊天界面对话框 else if((servlog->magic==0x54) && (servlog->flags==0x01)) ::MessageBox(NULL,"登录失败","system error",MB_OK|MB_ICONERROR); else ::MessageBox(NULL,"数据包不在服务范围内","system error",MB_OK|MB_ICONERROR); } } }}