高分!!!!!!!!!!如何在网上取得准确的时间?

[noname1]

就如同打电话117查时间一样?

[noname1]

多谢你,
我这里有一个软件,是中科院天文所出的一个网上对时的软件,对时服务器就是它们的,地址是kxzh.sxso.ac.cn,可是这个软件上有一个"连接服务器"按钮,还有一个"申请时间"按钮,说明它不是连接上就自动发给我的.有什么方法可查出这个软件的对时方法?用sniffer可以吗?
我在离线时打netstat /na显示结果出下:

Active Connections

Proto Local Address Foreign Address State
TCP 127.0.0.1:13 0.0.0.0:0 LISTENING
UDP 127.0.0.1:13 *:*

看来它是开的是我的13端口,不是服务器的.

[comanx]

Charles Petzold 的Programming Windows Fifth Edition上的第23章有一Winsock程序范例，就是对时的。

[ycp2000]

guanzhu

[土豆]

传统TCP服务，协议定义在RFC867中，DayTime服务接受指定端口的连接，向客户机发送一行标识当前日期和时间的文本。
DayTime的传统端口为13,通过SOCKET编程可以得到的，当然，你需要指定服务器。

[noname1]

网上有这本书的源码吗?

[noname1]

在网上浏览时会弹出一些讨厌的广告窗口,由其是网易的个人主页,真是叫人倒胃.一个一个的关掉十分麻烦,如果不关又会占系统资源,有了这个软件就好了,它可以自动关闭弹出的广告窗口,你会看到一个窗口弹出后约一秒就自动消失了,就是被本软件给关了.
网易最近又做了改版,原来的版本不管用了,还把广告窗口内容由原来的小广告条换成了网易的首页,真是令我等广大网虫气愤,所以我也出了新版,对付网易的广告窗口有特效!其它的广告窗口也有用.

[noname1]

多谢,那么给它发什么指令才能给我发时间文本

[tigerjade]

不用发任何指令，只要与端口建立连接，它就自动发送时间，然后它主动断开连接。

[comanx]

/*-------------------------------------------------------
NETTIME.C -- Sets System Clock from Internet Services

(c) Charles Petzold, 1998
-------------------------------------------------------*/

#include <windows.h>
#include "resource.h"

#define WM_SOCKET_NOTIFY (WM_USER + 1) //定义消息
#define ID_TIMER 1

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ; //窗口过程
BOOL CALLBACK MainDlg (HWND, UINT, WPARAM, LPARAM) ; //主对话框过程
BOOL CALLBACK ServerDlg (HWND, UINT, WPARAM, LPARAM) ; //选择服务器对话框过程

void ChangeSystemTime (HWND hwndEdit, ULONG ulTime) ; //改变系统时间的函数
void FormatUpdatedTime (HWND hwndEdit, SYSTEMTIME * pstOld,
SYSTEMTIME * pstNew) ; //格式化时间
void EditPrintf (HWND hwndEdit, TCHAR * szFormat, ...) ;

HINSTANCE hInst ;
HWND hwndModeless ;

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
PSTR szCmdLine, int iCmdShow)
{
static TCHAR szAppName[] = TEXT ("NetTime") ;
HWND hwnd ;
MSG msg ;
RECT rect ;
WNDCLASS wndclass ;

hInst = hInstance ;

wndclass.style = 0 ;
wndclass.lpfnWndProc = WndProc ;
wndclass.cbClsExtra = 0 ;
wndclass.cbWndExtra = 0 ;
wndclass.hInstance = hInstance ;
wndclass.hIcon = LoadIcon (NULL, IDI_APPLICATION) ;
wndclass.hCursor = NULL ;
wndclass.hbrBackground = NULL ;
wndclass.lpszMenuName = NULL ;
wndclass.lpszClassName = szAppName ;

if (!RegisterClass (&wndclass))
{
MessageBox (NULL, TEXT ("This program requires Windows NT!"),
szAppName, MB_ICONERROR) ;
return 0 ;
}

hwnd = CreateWindow (szAppName, TEXT ("Set System Clock from Internet"),
WS_OVERLAPPED | WS_CAPTION | WS_SYSMENU |
WS_BORDER | WS_MINIMIZEBOX,
CW_USEDEFAULT, CW_USEDEFAULT,
CW_USEDEFAULT, CW_USEDEFAULT,
NULL, NULL, hInstance, NULL) ;

// Create the modeless dialog box to go on top of the window

hwndModeless = CreateDialog (hInstance, szAppName, hwnd, MainDlg) ;

// Size the main parent window to the size of the dialog box.
// Show both windows.

GetWindowRect (hwndModeless, &rect) ;
AdjustWindowRect (&rect, WS_CAPTION | WS_BORDER, FALSE) ;

SetWindowPos (hwnd, NULL, 0, 0, rect.right - rect.left,
rect.bottom - rect.top, SWP_NOMOVE) ;

ShowWindow (hwndModeless, SW_SHOW) ;
ShowWindow (hwnd, iCmdShow) ;
UpdateWindow (hwnd) ;

// Normal message loop when a modeless dialog box is used.

while (GetMessage (&msg, NULL, 0, 0))
{
if (hwndModeless == 0 || !IsDialogMessage (hwndModeless, &msg))
{
TranslateMessage (&msg) ;
DispatchMessage (&msg) ;
}
}
return msg.wParam ;
}

LRESULT CALLBACK WndProc (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
switch (message)
{
case WM_SETFOCUS:
SetFocus (hwndModeless) ;
return 0 ;

case WM_DESTROY:
PostQuitMessage (0) ;
return 0 ;
}
return DefWindowProc (hwnd, message, wParam, lParam) ;
}

BOOL CALLBACK MainDlg (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static char szIPAddr[32] = { "132.163.135.130" } ;
static HWND hwndButton, hwndEdit ;
static SOCKET sock ;
static struct sockaddr_in sa ;
static TCHAR szOKLabel[32] ;
int iError, iSize ;
unsigned long ulTime ;
WORD wEvent, wError ;
WSADATA WSAData ;

switch (message)
{
case WM_INITDIALOG:
hwndButton = GetDlgItem (hwnd, IDOK) ;
hwndEdit = GetDlgItem (hwnd, IDC_TEXTOUT) ;
return TRUE ;

case WM_COMMAND:
switch (LOWORD (wParam))
{
case IDC_SERVER:
DialogBoxParam (hInst, TEXT ("Servers"), hwnd, ServerDlg,
(LPARAM) szIPAddr) ;
return TRUE ;

case IDOK:
// Call "WSAStartup" and display description text

if (iError = WSAStartup (MAKEWORD(2,0), &WSAData))
{
EditPrintf (hwndEdit, TEXT ("Startup error #%i.\r\n"),
iError) ;
return TRUE ;
}
EditPrintf (hwndEdit, TEXT ("Started up %hs\r\n"),
WSAData.szDescription);

// Call "socket"

sock = socket (AF_INET, SOCK_STREAM, IPPROTO_TCP) ;

if (sock == INVALID_SOCKET)
{
EditPrintf (hwndEdit,
TEXT ("Socket creation error #%i.\r\n"),
WSAGetLastError ()) ;
WSACleanup () ;
return TRUE ;
}
EditPrintf (hwndEdit, TEXT ("Socket %i created.\r\n"), sock) ;

// Call "WSAAsyncSelect"

if (SOCKET_ERROR == WSAAsyncSelect (sock, hwnd, WM_SOCKET_NOTIFY,
FD_CONNECT | FD_READ))
{
EditPrintf (hwndEdit,
TEXT ("WSAAsyncSelect error #%i.\r\n"),
WSAGetLastError ()) ;
closesocket (sock) ;
WSACleanup () ;
return TRUE ;
}

// Call "connect" with IP address and time-server port

sa.sin_family = AF_INET ;
sa.sin_port = htons (IPPORT_TIMESERVER) ;
sa.sin_addr.S_un.S_addr = inet_addr (szIPAddr) ;

connect(sock, (SOCKADDR *) &sa, sizeof (sa)) ;

// "connect" will return SOCKET_ERROR because even if it
// succeeds, it will require blocking. The following only
// reports unexpected errors.

if (WSAEWOULDBLOCK != (iError = WSAGetLastError ()))
{
EditPrintf (hwndEdit, TEXT ("Connect error #%i.\r\n"),
iError) ;
closesocket (sock) ;
WSACleanup () ;
return TRUE ;
}
EditPrintf (hwndEdit, TEXT ("Connecting to %hs..."), szIPAddr) ;

// The result of the "connect" call will be reported
// through the WM_SOCKET_NOTIFY message.
// Set timer and change the button to "Cancel"

SetTimer (hwnd, ID_TIMER, 1000, NULL) ;
GetWindowText (hwndButton, szOKLabel, sizeof (szOKLabel) /
sizeof (TCHAR)) ;
SetWindowText (hwndButton, TEXT ("Cancel")) ;
SetWindowLong (hwndButton, GWL_ID, IDCANCEL) ;
return TRUE ;

case IDCANCEL:
closesocket (sock) ;
sock = 0 ;
WSACleanup () ;
SetWindowText (hwndButton, szOKLabel) ;
SetWindowLong (hwndButton, GWL_ID, IDOK) ;

KillTimer (hwnd, ID_TIMER) ;
EditPrintf (hwndEdit, TEXT ("\r\nSocket closed.\r\n")) ;
return TRUE ;

case IDC_CLOSE:
if (sock)
SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;

DestroyWindow (GetParent (hwnd)) ;
return TRUE ;
}
return FALSE ;

case WM_TIMER:
EditPrintf (hwndEdit, TEXT (".")) ;
return TRUE ;

case WM_SOCKET_NOTIFY:
wEvent = WSAGETSELECTEVENT (lParam) ; // ie, LOWORD
wError = WSAGETSELECTERROR (lParam) ; // ie, HIWORD

// Process two events specified in WSAAsyncSelect

switch (wEvent)
{
// This event occurs as a result of the "connect" call

case FD_CONNECT:
EditPrintf (hwndEdit, TEXT ("\r\n")) ;

if (wError)
{
EditPrintf (hwndEdit, TEXT ("Connect error #%i."),
wError) ;
SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
return TRUE ;
}
EditPrintf (hwndEdit, TEXT ("Connected to %hs.\r\n"), szIPAddr) ;

// Try to receive data. The call will generate an error
// of WSAEWOULDBLOCK and an event of FD_READ

recv (sock, (char *) &ulTime, 4, MSG_PEEK) ;
EditPrintf (hwndEdit, TEXT ("Waiting to receive...")) ;
return TRUE ;

// This occurs even when the "recv" call can be made

case FD_READ:
KillTimer (hwnd, ID_TIMER) ;
EditPrintf (hwndEdit, TEXT ("\r\n")) ;

if (wError)
{
EditPrintf (hwndEdit, TEXT ("FD_READ error #%i."),
wError) ;
SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
return TRUE ;
}
// Get the time and swap the bytes

iSize = recv (sock, (char *) &ulTime, 4, 0) ;
ulTime = ntohl (ulTime) ;
EditPrintf (hwndEdit,
TEXT ("Received current time of %u seconds ")
TEXT ("since Jan. 1 1900.\r\n"), ulTime) ;

// Change the system time

ChangeSystemTime (hwndEdit, ulTime) ;
SendMessage (hwnd, WM_COMMAND, IDCANCEL, 0) ;
return TRUE ;
}
return FALSE ;
}
return FALSE ;
}

BOOL CALLBACK ServerDlg (HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
static char * szServer ;
static WORD wServer = IDC_SERVER1 ;
char szLabel [64] ;

switch (message)
{
case WM_INITDIALOG:
szServer = (char *) lParam ;
CheckRadioButton (hwnd, IDC_SERVER1, IDC_SERVER10, wServer) ;
return TRUE ;

case WM_COMMAND:
switch (LOWORD (wParam))
{
case IDC_SERVER1:
case IDC_SERVER2:
case IDC_SERVER3:
case IDC_SERVER4:
case IDC_SERVER5:
case IDC_SERVER6:
case IDC_SERVER7:
case IDC_SERVER8:
case IDC_SERVER9:
case IDC_SERVER10:
wServer = LOWORD (wParam) ;
return TRUE ;

case IDOK:
GetDlgItemTextA (hwnd, wServer, szLabel, sizeof (szLabel)) ;
strtok (szLabel, "(") ;
strcpy (szServer, strtok (NULL, ")")) ;
EndDialog (hwnd, TRUE) ;
return TRUE ;

case IDCANCEL:
EndDialog (hwnd, FALSE) ;
return TRUE ;
}
break ;
}
return FALSE ;
}

void ChangeSystemTime (HWND hwndEdit, ULONG ulTime)
{
FILETIME ftNew ;
LARGE_INTEGER li ;
SYSTEMTIME stOld, stNew ;

GetLocalTime (&stOld) ;

stNew.wYear = 1900 ;
stNew.wMonth = 1 ;
stNew.wDay = 1 ;
stNew.wHour = 0 ;
stNew.wMinute = 0 ;
stNew.wSecond = 0 ;
stNew.wMilliseconds = 0 ;
SystemTimeToFileTime (&stNew, &ftNew) ;
li = * (LARGE_INTEGER *) &ftNew ;
li.QuadPart += (LONGLONG) 10000000 * ulTime ;
ftNew = * (FILETIME *) &li ;
FileTimeToSystemTime (&ftNew, &stNew) ;

if (SetSystemTime (&stNew))
{
GetLocalTime (&stNew) ;
FormatUpdatedTime (hwndEdit, &stOld, &stNew) ;
}
else
EditPrintf (hwndEdit, TEXT ("Could NOT set new date and time.")) ;
}

void FormatUpdatedTime (HWND hwndEdit, SYSTEMTIME * pstOld, SYSTEMTIME * pstNew)
{
TCHAR szDateOld [64], szTimeOld [64], szDateNew [64], szTimeNew [64] ;

GetDateFormat (LOCALE_USER_DEFAULT, LOCALE_NOUSEROVERRIDE | DATE_SHORTDATE,
pstOld, NULL, szDateOld, sizeof (szDateOld)) ;

GetTimeFormat (LOCALE_USER_DEFAULT, LOCALE_NOUSEROVERRIDE |
TIME_NOTIMEMARKER | TIME_FORCE24HOURFORMAT,
pstOld, NULL, szTimeOld, sizeof (szTimeOld)) ;

GetDateFormat (LOCALE_USER_DEFAULT, LOCALE_NOUSEROVERRIDE | DATE_SHORTDATE,
pstNew, NULL, szDateNew, sizeof (szDateNew)) ;

GetTimeFormat (LOCALE_USER_DEFAULT, LOCALE_NOUSEROVERRIDE |
TIME_NOTIMEMARKER | TIME_FORCE24HOURFORMAT,
pstNew, NULL, szTimeNew, sizeof (szTimeNew)) ;

EditPrintf (hwndEdit,
TEXT ("System date and time successfully changed ")
TEXT ("from\r\n\t%s, %s.%03i to\r\n\t%s, %s.%03i."),
szDateOld, szTimeOld, pstOld->wMilliseconds,
szDateNew, szTimeNew, pstNew->wMilliseconds) ;
}

void EditPrintf (HWND hwndEdit, TCHAR * szFormat, ...)
{
TCHAR szBuffer [1024] ;
va_list pArgList ;

va_start (pArgList, szFormat) ;
wvsprintf (szBuffer, szFormat, pArgList) ;
va_end (pArgList) ;

SendMessage (hwndEdit, EM_SETSEL, (WPARAM) -1, (LPARAM) -1) ;
SendMessage (hwndEdit, EM_REPLACESEL, FALSE, (LPARAM) szBuffer) ;
SendMessage (hwndEdit, EM_SCROLLCARET, 0, 0) ;
}

[hatname]

在网上是不可能取得完全准确时间的。真的，

因为服务器发给你的时间是它当时的时间。数据通过网络是需要时间的。
一般的解决方法是计算通信的延时。调整得到的。