windows下udp连接&解决丢包现象

服务端：

#pragma comment (lib,"ws2_32.lib")

int _tmain(int argc, _TCHAR* argv[])
{   
	WSADATA wsaData; 
	int error=WSAStartup(MAKEWORD(1,1),&wsaData);
	if(error!=0)
	{
		return -1;
	}

	if(LOBYTE(wsaData.wVersion)!=1 || HIBYTE(wsaData.wVersion)!=1)
	{
		WSACleanup();
		return -1;
	}

	SOCKET s=socket(AF_INET,SOCK_DGRAM,0);
	SOCKADDR_IN sockSrc;
	sockSrc.sin_addr.S_un.S_addr=htonl(INADDR_ANY);
	sockSrc.sin_port=htons(8888);
	sockSrc.sin_family=AF_INET;

	bind(s,(SOCKADDR *)&sockSrc,sizeof(SOCKADDR));

	unsigned char recBuff[32*1024];
	setsockopt(s,SOL_SOCKET,SO_RCVBUF,(const char*)&recBuff,sizeof(int));
	memset(recBuff,0,32*1024);
 
	SOCKADDR_IN sockRec;
	int len=sizeof(SOCKADDR);
	int x=-1;
	int i = 1;
	FILE* pf;
	
	if(0 != fopen_s(&pf, ".//receive.txt","a+"))
	{
		printf("fopen error!\n");
	}
	while(1)
	{
		x=recvfrom(s,(char*)recBuff,sizeof(recBuff),0,(sockaddr *)&sockRec,&len); 
		printf("the receive is:\n"); 
		for(int i = 0; i < x; i++)
		{
			printf("%d",recBuff[i]);
		}
		printf("\n");
		fwrite(recBuff,x,1,pf);
		memset(recBuff,0,32*1024);
		printf("receive:%d  num is %d============================\n",x,i++);
	}

	closesocket(s);
	fclose(pf);
	WSACleanup();
	return 0;
}

客户端：

#include "stdafx.h"
#pragma comment (lib,"ws2_32.lib")


int _tmain(int argc, _TCHAR* argv[])
{
	WORD wVersionRequested;
	WSADATA wsaData;
	int err;
 
	wVersionRequested = MAKEWORD( 1, 1 );
 
	 err = WSAStartup( wVersionRequested, &wsaData );
	if ( err != 0 ) 
	{
		return -1;
	}
 
	if ( LOBYTE( wsaData.wVersion ) != 1 ||HIBYTE( wsaData.wVersion ) != 1 ) 
	{
		WSACleanup( );
		return -1; 
	}
	SOCKET sockClient=socket(AF_INET,SOCK_DGRAM,0);
	SOCKADDR_IN addrSrv;
	addrSrv.sin_addr.S_un.S_addr=inet_addr("192.168.31.127");
	addrSrv.sin_family=AF_INET;
	addrSrv.sin_port=htons(8888);
	while(1)
	{
		sendto(sockClient,"Hello",strlen("Hello")+1,0,(SOCKADDR*)&addrSrv,sizeof(SOCKADDR));
	}
	closesocket(sockClient);
	WSACleanup();
	return 0;
}

服务端发送的数据是5*256个char数据，在编写服务端的时候，我把缓存区设置为char [2000]；然后打印每次收到的数据。然后发现有丢包现象。后来经指导。讲缓存区改大了。问题就解决了。

在编写服务端的时候，我把缓存区设置为char [2000]；用来接收服务端发送过来的数据。服务端

int nRecvBuf=32*1024;//设置为32K,改一下设置

然后通过setsockopt这个函数来通知socket。
setsockopt(s,SOL_SOCKET,SO_RCVBUF,(const char*)&nRecvBuf,sizeof(int));

在编写服务端的时候，我把缓存区设置为char [2000]；用来接收服务端发送过来的数据。服务端