4.4.7 发送数据

　　显示客户端问候语之后，服务器向客户端发送应答。SendLine()函数用于发送数据。

         //向客户端发送数据

         strcpy(bufSend, "Hello,Client!/n");

         if (!SendLine(sClient, bufSend))

         {

                   return        ExitClient(SERVER_API_ERROR);

         }

在SendLine函数中，调用send()函数将"Hello,Client!/n"字符串发送给客户端。当该函数返回SOCKET_ERROR时，调用WSAGetLastError()函数得到错误代码，并调用ShowSocketMsg()函数将错误的字符串显示出来。SendLine()函数程序清单如下。

 

/*

 *      发送一行数据

 */

BOOL        SendLine(SOCKET s, char* str)

{

         int retVal;//返回值

         retVal = send(s, str, strlen(str), 0);                       //一次发送

 

         //错误处理

         if (SOCKET_ERROR == retVal)

         {

                   int nErrCode = WSAGetLastError();            //错误代码

                   if (WSAENOTCONN == nErrCode)

                   {

                            ShowSocketMsg("The socket is not connected!");

                           

                   }else if(WSAESHUTDOWN == nErrCode)

                   {

                            ShowSocketMsg("The socket has been shut down!");

                           

                   }else if (WSAETIMEDOUT == nErrCode)

                   {

                            ShowSocketMsg("The connection has been dropped!");

                   }else{}      

                  

                   return FALSE;                                                  //发送失败

         }

        

         return TRUE;                                                            //发送成功

}