使用winsock+UDP写的一个简单发送端程序（转）

本程序使用VS2008编写，代码如下：

 

#include <winsock2.h>
#include <stdio.h>
//在编译采用了WINSOCK2.H的应用程序时，需要链接到WS2_32.LIB库
#pragma comment(lib,"WS2_32.LIB")
void main()
{
    WSADATA          wsaData;
    SOCKET           SendingSocket;
    SOCKADDR_IN      ReceiverAddr;
    int              Port = 8060;
//  char             SendBuf[1024] = {1};
//  int              BufLength = 1024;

    int              Ret;
    //初始化Winsock 2.2版本
    if((Ret = WSAStartup(MAKEWORD(2,2),&wsaData)) !=0)
    {
        printf("ERROR:WSAStartup failed with %d/n",Ret);
        return;
    }
    //创建一个新的套接字来接收数据报
    if((SendingSocket = socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP)) == INVALID_SOCKET)
    {
        printf("ERROR:SOCKET failed with %d/n",WSAGetLastError());
        WSACleanup();
        return;
    }
    //建立一个SOCKADDR_IN结构，来识别发送数据报的目的地
    ReceiverAddr.sin_family = AF_INET;
    ReceiverAddr.sin_port = htons(Port);
    ReceiverAddr.sin_addr.s_addr = inet_addr("127.0.0.1");
    //把一个数据报发送到接收者
    if((Ret = sendto(SendingSocket,"hello",5,0,(SOCKADDR *)&ReceiverAddr,sizeof(ReceiverAddr)))
        == SOCKET_ERROR)
    {
        printf("ERROR: sendto failed with error %d/n", WSAGetLastError());
        closesocket(SendingSocket);
        WSACleanup();
        return;
    }
    //应用程序完成发送数据报后，关闭套接字
    closesocket(SendingSocket);
    //应用程序结束后 ，调用WSACleanup
    WSACleanup();
}