《孙鑫VC视频》- UDP网络编程

服务器端（接收端）程序：
1、创建套接字（socket）。
2、将套接字绑定到一个本地地址和端口上（bind）。
3、等待接收数据（recvfrom）。
4、关闭套接字。

客户端（发送端）程序：
1、创建套接字（socket）。
2、向服务器发送数据（sendto）。
3、关闭套接字。

服务器端代码：

/*
 *UDP Server 
 *2008-12-04
 */
#include <winsock2.h>
#include <stdio.h>

void main(){
	//初始化
	WORD wVersionRequired;
	WSAData wsaData;
	wVersionRequired = MAKEWORD(2,2);
	
	WSAStartup(wVersionRequired,&wsaData);

	//创建socket
	SOCKET server;
	server = socket(AF_INET,SOCK_DGRAM,0);

	//绑定
	SOCKADDR_IN addr;
	addr.sin_family = AF_INET;
	addr.sin_addr.S_un.S_addr = htonl(INADDR_ANY);
	addr.sin_port = htons(6006);
	bind(server,(SOCKADDR*)&addr,sizeof(SOCKADDR));
	
	//接收
	char recvBuf[100];
	int recvLen;
	SOCKADDR_IN clientAddr;
	int fromLen;
	recvLen = 100;
	fromLen = sizeof(SOCKADDR);
	recvfrom(server,recvBuf,recvLen,0,(SOCKADDR*)&clientAddr,&fromLen);
	printf("Receive:%s",recvBuf);

	//发送
	char * sendBuf;
	int sendLen;
	sendBuf = "Message from Server!\n";
	sendLen = strlen(sendBuf) + 1;
	sendto(server,sendBuf,sendLen,0,(SOCKADDR*)&clientAddr,fromLen);

	//关闭
	closesocket(server);
	WSACleanup();
}

 

客户端程序:

/*
 *UDP Client 
 *2008-12-04
 */
#include <winsock2.h>
#include <stdio.h>

void main(){
	WORD wVersionRequired;
	WSAData wsaData;
	wVersionRequired = MAKEWORD(2,2);
	WSAStartup(wVersionRequired,&wsaData);

	SOCKET client;
	client = socket(AF_INET,SOCK_DGRAM,0);

	char sendBuf[100];
	int len;
	SOCKADDR_IN addr;
	int toLen;
	char *temp = "Message from Client!\n";
	sprintf(sendBuf,"%s",temp);
	len = strlen(sendBuf)+1;
	addr.sin_family = AF_INET;
	addr.sin_addr.S_un.S_addr = inet_addr("127.0.0.1");
	addr.sin_port = htons(6006);
	toLen = sizeof(SOCKADDR);
	sendto(client,sendBuf,len,0,(SOCKADDR*)&addr,toLen);

	char recvBuf[100];
	int recvLen;
	SOCKADDR_IN addr_in;
	int fromLen;
	recvLen = 100;
	fromLen = sizeof(SOCKADDR);
	recvfrom(client,recvBuf,recvLen,0,(SOCKADDR*)&addr_in,&fromLen);
	printf("Receive:%s",recvBuf);

	closesocket(client);
	WSACleanup();
}