基于UDP Socket例子

客户端程序代码如下：

#pragma comment(lib,"ws2_32.lib")
#include<winsock2.h>
#include<stdio.h>
BOOL InitWinsock();
void main()
{
	SOCKET socket1;
	InitWinsock();
	struct sockaddr_in server;
	int len=sizeof(server);
	server.sin_family=AF_INET;
	server.sin_port=htons(1000);	//Server的监听端口为1000
	server.sin_addr.s_addr=inet_addr("192.168.0.199");
	socket1=socket(AF_INET,SOCK_DGRAM,0);
	while(1)
	{
		char buffer[1024]="\0";
		printf("input message\n");
		scanf("%s",buffer);
		if(strcmp(buffer,"bye")==0)
			break;
		if(sendto(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&server,len)!=SOCKET_ERROR)
		{
			if(recvfrom(socket1,buffer,sizeof(buffer),0,(struct sockaddr *)&server,&len)!=SOCKET_ERROR)
				printf("rece from server:%s\n",buffer);
		}
	}
	closesocket(socket1);
}

BOOL InitWinsock()
{
	int Error;
	WORD VersionRequested;
	WSADATA WsaData;
	VersionRequested=MAKEWORD(2,2);
	Error=WSAStartup(VersionRequested,&WsaData);
	if(Error!=0)
	{
		return FALSE;
	}
	else
	{
		if(LOBYTE(WsaData.wVersion)!=2||HIBYTE(WsaData.wHighVersion)!=2)
		{
			WSACleanup();
			return FALSE;
		}
	}
	return TRUE;
}

 //htons()的功能：将一个无符号短整型数值转换为网络字节序，即大端模式(big-endian)

服务端程序代码：

#pragma comment(lib,"ws2_32.lib")
#include<winsock2.h>
#include<stdio.h>
BOOL InitWinsock();
void main()
{
	SOCKET socket1;
	InitWinsock();
	struct sockaddr_in local;
	struct sockaddr_in from;
	int fromlen=sizeof(from);
	local.sin_family=AF_INET;
	local.sin_port=htons(1000);　　//监听端口
	local.sin_addr.s_addr=INADDR_ANY;　　//本机
	socket1=socket(AF_INET,SOCK_DGRAM,0);
	bind(socket1,(struct sockaddr*)&local,sizeof(local));
	while(1)
	{
		char buffer[1024]="\0";
		printf("waiting for message from others-------------");
		if(recvfrom(socket1,buffer,sizeof(buffer),0,(struct sockaddr*)&from,&fromlen)!=SOCKET_ERROR)
		{
			printf("Received datagram from %s--%s\n",inet_ntoa(from.sin_addr),buffer);
　　　　　　　　　　　　　　//给Client发信息
			sendto(socket1,strcat(buffer,"hello"),sizeof(strcat(buffer,"hello")),0,(struct sockaddr*)&from,fromlen);
			printf("%s",buffer);
		}
		Sleep(500);
	}
	closesocket(socket1);
}
BOOL InitWinsock()
{
	int Error;
	WORD VersionRequested;
	WSADATA WsaData;
	VersionRequested=MAKEWORD(2,2);
	Error=WSAStartup(VersionRequested,&WsaData);
	if(Error!=0)
	{
		return FALSE;
	}
	else
	{
		if(LOBYTE(WsaData.wVersion)!=2||HIBYTE(WsaData.wHighVersion)!=2)
		{
			WSACleanup();
			return FALSE;
		}
	}
	return TRUE;
}