win32 socket编程帮助-优快云博客

本文介绍使用Winsock进行异步客户端编程的基本步骤。包括创建套接字、填充SOCKADDR_IN结构体、连接服务器、发送接收数据及关闭套接字等过程。

http://msdn.microsoft.com/en-us/library/ms741394(v=vs.85)

client:

Socket programming in MFC is usually a bit messy. It's always clean and convenient to write the socket programs using Win32.

A big advantage writing these programs in Win32 is, we can follow the same model as in any Unix C++ socket program. Also, with each and every new version of Winsock, we don't know how many bugs are going to get added to the development frameworks.

Anyway, now let's get down to business. This article does not try to cover all the minute details of winsock client programming, but for the basics. The relevant steps for creating a synchronous client socket are:

Create a socket and get the handle
Populate the SOCKADDR_IN structure with the Server IP and Port Number
Connect using the connect function
Send and Recv using the socket
Shutdown and Close when all jobs are done

The following sample illustrates the above steps. Only one item missed out here is the usage of recv function.

#include <winsock2.h>
#include <iostream.h>
int gPort = 8780;
void main()
{
       SOCKET lhSocket;
       SOCKADDR_IN lSockAddr;
       WSADATA wsaData;
       int lConnect;
       int lLength;
       char lData[]="SendData";
       if(WSAStartup(MAKEWORD(2,0),&wsaData) != 0)
       {
            cout<<"Socket Initialization Error. Program aborted\n";
            return;
        }
       lhSocket = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
       if(lhSocket == INVALID_SOCKET)
       {
            cout<<"Invalid Socket "<<GetLastError()<<". Program Aborted\n"<<endl;
        }
       memset(&lSockAddr,0, sizeof(lSockAddr));
       lSockAddr.sin_family = AF_INET;
       lSockAddr.sin_port = htons(gPort);
       lSockAddr.sin_addr.s_addr = inet_addr("IPAddress");
       lConnect = connect(lhSocket,(SOCKADDR *)&lSockAddr,sizeof(SOCKADDR_IN));
       if(lConnect != 0)
       {
             cout<<"Connect Error. Program aborted\n";
             return;
        }
       lLength = send(lhSocket,lData,strlen(lData),0);
       if(lLength < strlen(lData))
       {
            cout<<"Send Error.\n";
       }
       closesocket(lhSocket);
       return;
}