error LNK2001: unresolved external symbol _main等.该如何处理

2013-07-04

error LNK2001: unresolved external symbol _main等.本帖最后由 oyljerry 于 2012-01-03 11:04:49 编辑#i

error LNK2001: unresolved external symbol _main等.
本帖最后由 oyljerry 于 2012-01-03 11:04:49 编辑 #include "stdafx.h"
#include <WinSock.h>
#include <time.h>
#include <windows.h>

#pragma comment (lib,"Ws2_32")

struct NTP_Packet
{
  int Control_Word;
  int root_delay;
  int root_dispersion;
  int reference_identifier;
  __int64 reference_timestamp;
  __int64 originate_timestamp;
  __int64 receive_timestamp;
  int transmit_timestamp_seconds;
  int transmit_timestamp_fractions;
};

/************************************************************************/
/* 函数说明:自动与时间服务器同步更新
/* 参数说明:无
/* 返回值:成功返回TRUE，失败返回FALSE
/************************************************************************/
BOOL UpdateSysTime()
{
  WORD wVersionRequested;
  WSADATA wsaData;

  // 初始化版本
  wVersionRequested = MAKEWORD( 1, 1 );
  if (0!=WSAStartup(wVersionRequested, &wsaData))
  {
  WSACleanup();
  return FALSE;
  }
  if (LOBYTE(wsaData.wVersion)!=1 || HIBYTE(wsaData.wVersion)!=1)
  {
  WSACleanup( );
  return FALSE;
  }

  // 这个IP是中国大陆时间同步服务器地址，可自行修改
  SOCKET soc=socket(AF_INET,SOCK_DGRAM,IPPROTO_UDP);
  struct sockaddr_in addrSrv;
  addrSrv.sin_addr.S_un.S_addr=inet_addr("192.43.244.18");
  addrSrv.sin_family=AF_INET;
  addrSrv.sin_port=htons(123);

  NTP_Packet NTP_Send,NTP_Recv;
  NTP_Send.Control_Word = htonl(0x0B000000);
  NTP_Send.root_delay = 0;
  NTP_Send.root_dispersion = 0;
  NTP_Send.reference_identifier = 0;
  NTP_Send.reference_timestamp = 0;
  NTP_Send.originate_timestamp = 0;
  NTP_Send.receive_timestamp = 0;
  NTP_Send.transmit_timestamp_seconds = 0;
  NTP_Send.transmit_timestamp_fractions = 0;

  if(SOCKET_ERROR==sendto(soc,(const char*)&NTP_Send,sizeof(NTP_Send),
  0,(struct sockaddr*)&addrSrv,sizeof(addrSrv)))
  {
  closesocket(soc);
  return FALSE;
  }

  int sockaddr_Size =sizeof(addrSrv);
  if(SOCKET_ERROR==recvfrom(soc,(char*)&NTP_Recv,sizeof(NTP_Recv),
  0,(struct sockaddr*)&addrSrv,&sockaddr_Size))
  {
  closesocket(soc);
  return FALSE;
  }
  closesocket(soc);
  WSACleanup();

  SYSTEMTIME newtime;
  float Splitseconds;
  struct tm *lpLocalTime;
  time_t ntp_time;

  // 获取时间服务器的时间
  ntp_time = ntohl(NTP_Recv.transmit_timestamp_seconds)-2208988800;
  lpLocalTime = localtime(&ntp_time);
  if(lpLocalTime == NULL)
  {
  return FALSE;
  }

  // 获取新的时间
  newtime.wYear =lpLocalTime->tm_year+1900;
  newtime.wMonth =lpLocalTime->tm_mon+1;
  newtime.wDayOfWeek =lpLocalTime->tm_wday;
  newtime.wDay =lpLocalTime->tm_mday;
  newtime.wHour =lpLocalTime->tm_hour;
  newtime.wMinute =lpLocalTime->tm_min;
  newtime.wSecond =lpLocalTime->tm_sec;

  // 设置时间精度
  Splitseconds=(float)ntohl(NTP_Recv.transmit_timestamp_fractions);
  Splitseconds=(float)0.000000000200 * Splitseconds;
  Splitseconds=(float)1000.0 * Splitseconds;
  newtime.wMilliseconds = (unsigned short)Splitseconds;

  // 修改本机系统时间
  SetLocalTime(&newtime);
  return TRUE;
}
此程序用于两台计算机对时与internet时间同步，
编译后出现错误:fatal error C1083: Cannot open include file: 'stdafx.h': No such file or directory
我创建的是windows console application，C/C++源程序，将#include "stdafx.h"这行去掉以后缺出现error LNK2001: unresolved external symbol _main，将console改成windows后又出现LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16，这两个错误交替出现的现象，就是project里边改成windows和console时候都不对，形成这种循环错误，这是怎么回事儿

[解决办法]
不管是控制台程序还是window程序，你总得有个入口函数吧。控制台你得有个main，windows程序你得要有个WinMain啊
[解决办法]
#pragma comment (lib,"Ws2_32.lib")
------解决方案--------------------

增加上main或者WinMain函数
还需要
#pragma comment (lib,"Ws2_32.lib")
[解决办法]
用VC编译器建立console工程，然后添加代码

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VC/MFC

error LNK2001: unresolved external symbol _main等.该如何处理