VC automatically synchronizes updates with Internet time servers

In the vckbase, Csdn dug a long tomb, only to find some kind of information, and finally sorted out such a function, the VC to achieve time synchronization, many do not say, their own view of the source, according to their own needs can be appropriate to modify the source code:

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2. #include <WinSock.h>
4. #pragma comment (lib, "Ws2_32")
8. struct Ntp_packet
10. {
12. int Control_word;
14. int root_delay;
16. int root_dispersion;
18. int reference_identifier;
20. __int64 Reference_timestamp;
22. __int64 Originate_timestamp;
24. __int64 Receive_timestamp;
26. int transmit_timestamp_seconds;
28. int transmit_timestamp_fractions;
30. };

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2. /************************************************************************/
4. /* Function Description: Automatically synchronize updates with the time server
6. /* Parameter Description: None
8. /* Return Value: Success returns TRUE, Failure returns false
10. /************************************************************************/
12. BOOL Updatesystime ()
14. {
16. WORD wversionrequested;
18. Wsadata Wsadata;
22. //Initialize version
24. wversionrequested = Makeword (1, 1);
26. if (0!=wsastartup (wversionrequested, &wsadata))
28. {
30. WSACleanup ();
32. return FALSE;
34. }
36. if (Lobyte (wsadata.wversion)!=1 | | Hibyte (wsadata.wversion)!=1)
38. {
40. WSACleanup ();
42. return FALSE;
44. }
48. //This IP is China mainland time synchronization server address, can be modified by itself
50. SOCKET Soc=socket (AF_INET,SOCK_DGRAM,IPPROTO_UDP);
52. struct sockaddr_in addrsrv;
54. Addrsrv.sin_addr. S_un.  S_addr=inet_addr ("210.72.145.44");
56. Addrsrv.sin_family=af_inet;
58. Addrsrv.sin_port=htons (123);
62. Ntp_packet Ntp_send,ntp_recv;
64. Ntp_send.control_word = htonl (0x0b000000);
66. Ntp_send.root_delay = 0;
68. ntp_send.root_dispersion = 0;
70. Ntp_send.reference_identifier = 0;
72. Ntp_send.reference_timestamp = 0;
74. Ntp_send.originate_timestamp = 0;
76. Ntp_send.receive_timestamp = 0;
78. ntp_send.transmit_timestamp_seconds = 0;
80. ntp_send.transmit_timestamp_fractions = 0;
84. if (Socket_error==sendto (Soc, (const char*) &ntp_send,sizeof (ntp_send),
86. 0, (struct sockaddr*) &addrsrv,sizeof (ADDRSRV)))
88. {
90. Closesocket (SOC);
92. return FALSE;
94. }
96. int sockaddr_size =sizeof (ADDRSRV);
98. if (Socket_error==recvfrom (Soc,char*) &ntp_recv,sizeof (NTP_RECV),
100. 0, (struct sockaddr*) &addrsrv,&sockaddr_size))
102. {
104. Closesocket (SOC);
106. return FALSE;
108. }
110. Closesocket (SOC);
112. WSACleanup ();
116. SYSTEMTIME NewTime;
118. float splitseconds;
120. struct TM *lplocaltime;
122. time_t ntp_time;
126. //Get time on server
128. Ntp_time = Ntohl (ntp_recv.transmit_timestamp_seconds)-2208988800;
130. Lplocaltime = LocalTime (&ntp_time);
132. if (lplocaltime = = NULL)
134. {
136. return FALSE;
138. }
142. //Get new Time
144. Newtime.wyear =lplocaltime->tm_year+1900;
146. Newtime.wmonth =lplocaltime->tm_mon+1;
148. Newtime.wdayofweek =lplocaltime->tm_wday;
150. Newtime.wday =lplocaltime->tm_mday;
152. Newtime.whour =lplocaltime->tm_hour;
154. Newtime.wminute =lplocaltime->tm_min;
156. Newtime.wsecond =lplocaltime->tm_sec;
160. //Set time accuracy
162. splitseconds= (float) Ntohl (ntp_recv.transmit_timestamp_fractions);
164. splitseconds= (float) 0.000000000200 * splitseconds;
166. splitseconds= (float) 1000.0 * splitseconds;
168. Newtime.wmilliseconds = (unsigned short ) splitseconds;
172. //Modify the native system time
174. Setlocaltime (&newtime);
176. return TRUE;
178. }

http://blog.csdn.net/wangningyu/article/details/4522648

VC automatically synchronizes updates with Internet time servers