vc 获取网络时间

方式1 :
#include <WinSock2.h>#include <Windows.h>#pragma comment(lib, "WS2_32") // 链á′接ó到μ?WS2_32.lib class CInitSock{ public: CInitSock(BYTE minorVer = 2, BYTE majorVer = 2) { // 初3?始ê?化ˉWS2_32.dll WSADATA wsaData; WORD sockVersion = MAKEWORD(minorVer, majorVer); if(::WSAStartup(sockVersion, &wsaData) != 0) { exit(0); } } ~CInitSock() { ::WSACleanup(); } };CInitSock initS;BOOL NistGetTime(LPFILETIME OutTime){ BOOL bOk; struct hostent *host; bOk = FALSE; if (host = gethostbyname("time.nist.gov")) { SOCKET s; in_addr ia; CHAR IpText[32]; memcpy(&ia, host->h_addr, host->h_length); lstrcpyA(IpText, inet_ntoa(ia)); s = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP); if (s != INVALID_SOCKET) { sockaddr_in sac; memset(&sac, 0, sizeof(sac)); sac.sin_family = AF_INET; sac.sin_port = htons(37); sac.sin_addr.s_addr = inet_addr(IpText); if (connect(s, (sockaddr*)&sac, sizeof(sac)) == 0) { ULONG nTime; if (recv(s, (PCHAR)&nTime, sizeof(nTime), 0) == sizeof(nTime)) { LONGLONG llt; nTime = ntohl(nTime); llt = 0x014F373BFDE04000;//1900.1.1 llt += LONGLONG(nTime) * 10000000; memcpy(OutTime, &llt, sizeof(FILETIME)); bOk = TRUE; } } closesocket(s); } } return bOk;}int _tmain(int argc, _TCHAR* argv[]){ FILETIME ft; CInitSock initS; NistGetTime(&ft); SYSTEMTIME st; FileTimeToSystemTime(&ft,&st); return 0;}

方式2 mfc:
CTime NistGetTime(){ //时间同步 CSocket sockClient; TIME_ZONE_INFORMATION tzinfo; DWORD dwStandardDaylight; long bias,sminute,shour; vector <string> vi; string strServer; BOOL ret; //将时间服务器放在一个VECTOR中。 strServer = "time.nist.gov"; vi.push_back(strServer); strServer = "time-a.nist.gov"; vi.push_back(strServer); strServer = "time-b.nist.gov"; vi.push_back(strServer); strServer = "time-nw.nist.gov"; vi.push_back(strServer); strServer = "nist1.nyc.certifiedtime.com"; vi.push_back(strServer); strServer = "time-b.nist.gov"; vi.push_back(strServer);
//初始化CSocket AfxSocketInit(); sockClient.Create(); //创建socket

dwStandardDaylight = GetTimeZoneInformation(&tzinfo); //获取时区与UTC的时间差 应该返回-8 bias = tzinfo.Bias; if (dwStandardDaylight == TIME_ZONE_ID_INVALID) //函数执行失败 { return; } if (dwStandardDaylight == TIME_ZONE_ID_STANDARD) //标准时间有效 bias += tzinfo.StandardBias;
if (dwStandardDaylight == TIME_ZONE_ID_DAYLIGHT) //夏令时间 bias += tzinfo.DaylightBias;
shour = bias/60; sminute = fmod((float)bias,60);
//循环判断服务器是否连接成功 for (int n=0; n < vi.size(); ++ n) { ret = sockClient.Connect(vi
.c_str(),13); if (1 == ret) break;
}
unsigned char nTime[100] = {0}; //临时接收数据要求足够的大
sockClient.Receive(nTime, sizeof(nTime)); //接收服务器发送来得的数据 sockClient.Close(); //关闭socket
CString strTime; strTime.Format("%s",nTime);
int first=strTime.Find("-"); int second=strTime.Find("-",first+1);
int tfirst = strTime.Find(":"); int tsecond = strTime.Find(":",tfirst+1);

int hyear=2000+atoi(strTime.Mid(first-2,2)); int hmonth=atoi(strTime.Mid(first+1,2)); int hday=atoi(strTime.Mid(second+1,2)); int hhour=atoi(strTime.Mid(tfirst-2,2))-shour; int hminute=atoi(strTime.Mid(tfirst+1,2))-sminute; int hsecond=atoi(strTime.Mid(tsecond+1,2)); CTime temptime(hyear,hmonth,hday,hhour,hminute,hsecond); return temptime;}

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