Windows API Guide: BY_HANDLE_FILE_INFORMATION Structure

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Declare Function CompareFileTime Lib "kernel32.dll" (lpFileTime1 As FILETIME, lpFileTime2 As FILETIME) As Long

Platforms: Win 32s, Win 95/98, Win NT

CompareFileTime compares two times stored in FILETIME format. The function determines which of the two times, if any, comes before the other chronologically. If the first time is earlier than the second time, the function returns -1. If the two times are equal, the function returns 0. If the first time is later than the second time, the function returns 1.

lpFileTime1

The first of the two times to compare.

lpFileTime2

The second of the two times to compare.

Example:

' Determine if file C:\MyProgram\datafile.txt was created before ' Jan 5, 1999.  Note how CreateFile's alternate declare must be used under Win 95/98 -- ' see that function's page for more information. Dim hfile As Long  ' receives the handle to the file Dim ctime As FILETIME  ' receives creation date and time of the file Dim atime As FILETIME  ' receives last access date and time of the file Dim wtime As FILETIME  ' receives last write-to date and time of the file Dim jantime As SYSTEMTIME  ' will be set to Jan 5, 1999 Dim janfiletime As FILETIME  ' will receive analogous time as jantime Dim comptimes As Long  ' receives comparison of ctime and janfiletime Dim retval As Long  ' return value ' Get a handle to the file (note how the alternate declare is used): hfile = CreateFileNS("C:\MyProgram\datafile.txt", GENERIC_READ, FILE_SHARE_READ, 0, OPEN_EXISTING, FILE_ATTRIBUTE_ARCHIVE, 0) If hfile = -1 Then  ' if the file could not be opened   Debug.Print "Could not open the file C:\MyProgram\datafile.txt."   End  ' abort the program End If ' Get the various times and dates associated with the file: retval = GetFileTime(hfile, ctime, atime, wtime) ' Load jantime with the date January 5, 1999 at midnight: jantime.wMonth = 1: jantime.wDay = 5: jantime.wYear = 1999 jantime.wHour = 0: jantime.wMinute = 0: jantime.wSecond = 0 ' Convert jantime into FILETIME format so it can be compared with ctime: retval = SystemTimeToFileTime(jantime, janfiletime) ' Compare the two times and display the relation: comptimes = CompareFileTime(ctime, janfiletime) If comptimes = -1 Then Debug.Print "File was created before midnight, January 5, 1999." If comptimes = 0 Then Debug.Print "File was created at midnight, January 5, 1999." If comptimes = 1 Then Debug.Print "File was created after midnight, January 5, 1999." ' Close the file retval = CloseHandle(hfile)

Category: Time

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