Obtain the last modified date of a file with MILLISECONDS?

≡放荡痞女 提交于 2019-12-23 23:03:42

问题


I am trying to get the date and time (last modified) of some files from a folder. I managed to get the date and hour/minutes/seconds but I can not get the milliseconds.

I already tried formatting the column in all the ways possible. I only get 0 for milliseconds.

My code so far does:

  • the user chooses a folder

  • the code displays in column A all the file names found and in column B the date, hour,minute and seconds (last modified date/time)

What should I do to the current code to obtain the milliseconds ?

This is my code:

Private Function GetAllFiles(ByVal strPath As String, _
    ByVal intRow As Integer, ByRef objFSO As Object) As Integer
    Dim objFolder As Object
    Dim objFile As Object
    Dim i As Integer
    i = intRow - ROW_FIRST + 1
    Set objFolder = objFSO.GetFolder(strPath)
    For Each objFile In objFolder.Files
        'print file name
        Cells(i + ROW_FIRST + 2, 1) = objFile.Name
        'print file path
        Cells(i + ROW_FIRST + 2, 2) = objFile.DateLastModified
        i = i + 1
    Next objFile
    GetAllFiles = i + ROW_FIRST - 1
End Function

回答1:


The following module will retrieve Windows file creation, modify or accessed datetime including milliseconds, using a Windows API call.

However it must be noted that there are a number of potential issues. A big one is that the VBA Date data type has a resolution of 1 second, so the datetime needs to be returned as a String, or stored in a different data type (Currency is the correct size.)

Option Explicit

Declare Function GetFileTime Lib "kernel32.dll" (ByVal hFile As Long, _
    lpCreationTime As FILETIME, lpLastAccessTime As FILETIME, _
    lpLastWriteTime As FILETIME) As Long

Declare Function CreateFile Lib "kernel32.dll" Alias "CreateFileA" _
    (ByVal lpFileName As String, ByVal dwDesiredAccess As Long, _
    ByVal dwShareMode As Long, lpSecurityAttributes As Any, _
    ByVal dwCreationDisposition As Long, ByVal dwFlagsAndAttributes As Long, _
    ByVal hTemplateFile As Long) As Long

Declare Function CloseHandle Lib "kernel32.dll" (ByVal hObject As Long) As Long

Declare Function FileTimeToSystemTime Lib "kernel32.dll" _
    (lpFileTime As FILETIME, lpSystemTime As SYSTEMTIME) As Long

Type FILETIME
dwLowDateTime As Long
dwHighDateTime As Long
End Type

Type SYSTEMTIME
wYear As Integer
wMonth As Integer
wDayOfWeek As Integer
wDay As Integer
wHour As Integer
wMinute As Integer
wSecond As Integer
wMilliseconds As Integer
End Type


Const GENERIC_READ = &H80000000
Const GENERIC_WRITE = &H40000000
Const FILE_SHARE_READ = &H1
Const FILE_SHARE_WRITE = &H2
Const CREATE_ALWAYS = 2
Const CREATE_NEW = 1
Const OPEN_ALWAYS = 4
Const OPEN_EXISTING = 3
Const TRUNCATE_EXISTING = 5
Const FILE_ATTRIBUTE_ARCHIVE = &H20
Const FILE_ATTRIBUTE_HIDDEN = &H2
Const FILE_ATTRIBUTE_NORMAL = &H80
Const FILE_ATTRIBUTE_READONLY = &H1
Const FILE_ATTRIBUTE_SYSTEM = &H4
Const FILE_FLAG_DELETE_ON_CLOSE = &H4000000
Const FILE_FLAG_NO_BUFFERING = &H20000000
Const FILE_FLAG_OVERLAPPED = &H40000000
Const FILE_FLAG_POSIX_SEMANTICS = &H1000000
Const FILE_FLAG_RANDOM_ACCESS = &H10000000
Const FILE_FLAG_SEQUENTIAL_SCAN = &H8000000
Const FILE_FLAG_WRITE_THROUGH = &H80000000

Function GetDateValue(fName As String) As String
'returns UTC (GMT) file time for specified file

    Dim hFile As Long ' handle to the opened file
    Dim ctime As FILETIME ' receives time of creation
    Dim atime As FILETIME ' receives time of last access
    Dim mtime As FILETIME ' receives time of last modification
    Dim Thetime As SYSTEMTIME ' used to manipulate the time
    Dim retval As Long ' return value

    hFile = CreateFile(fName, GENERIC_READ, FILE_SHARE_READ, _
        ByVal CLng(0), OPEN_EXISTING, FILE_ATTRIBUTE_ARCHIVE, 0)

    retval = GetFileTime(hFile, ctime, atime, mtime)

    'Choose which date to return: creation, modify or access date
    'retval = FileTimeToSystemTime(ctime, Thetime) 'extract creation datetime
    retval = FileTimeToSystemTime(mtime, Thetime) 'extract modified datetime
    'retval = FileTimeToSystemTime(atime, Thetime) 'extract accessed datetime

    retval = CloseHandle(hFile)

    With Thetime
        GetDateValue = .wYear & Format(.wMonth, "\-00") & _
            Format(.wDay, "\-00") & " " & Format(.wHour, "00") & _
            Format(.wMinute, "\:00") & Format(.wSecond, "\:00") & _
            Format(.wSecond, "\.000")
    End With
End Function

Sub test()
    MsgBox GetDateValue("c:\logfile.txt") 
    'returns a string like "2018-03-31 16:13:52.052"
End Sub

I'm just pasting this here, it isn't perfect but it works and can be adjusted to your individual needs. Note that you need to manually uncomment the line for which datetime you want the function to return.

Be sure to read up before you use this for anything important because there are limitations depending on your file system and more. For example, NTFS will often finish writing a file after you "think" it's finished... up to 1 hour later.


More Information:

  • VB Forumus: Code Source (note the author's error mentioned in his following post.)

  • MSDN : Windows File Times

  • MSDN : GetFileTime Function (Windows/C++)

  • Stack Overflow : VBA String with Milliseconds to Date



来源:https://stackoverflow.com/questions/49649562/obtain-the-last-modified-date-of-a-file-with-milliseconds

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