.net - GetLastWriteTime 不准确

Question

我正在使用一个函数来检查远程计算机上文件的时间戳。我们有很多电脑。

我遇到的事情有点奇怪。

我在很多计算机上运行查询。 Computer26887 上的时间戳显示为“1/4/2013 12:46:01 AM”
我 UNC 到那台计算机并检查文件。在资源管理器中，时间戳显示“9/16/2013 11:23 AM”(一个半小时前)嗯....
再次查询 - 旧的，错误的，时间戳。我右键单击该文件，转到属性并单击属性窗口中的“详细信息”-“修改日期 9/16/2013 11:23 AM”
使用 vb 代码再次查询 - 现在它显示了正确的时间戳？？？？

我有数百个系统要通过，如果我不能相信我得到的数据，我有太多的工作要做!!!

有任何想法吗？

更新
基本上，VB.NET 正在检索时间戳的缓存版本。时间戳已更新，但缓存仍保留旧时间戳。如何在不手动打开资源管理器中文件属性的情况下强制更新缓存？

Shared Function GetFileInfo(ByVal ComputerName As String, ByVal FiletoFind As String, info As String)
    Dim Ret As String = ""
    Dim targetfile = "\\" & ComputerName & "\" & FiletoFind
    Dim fi As FileInfo = New FileInfo(targetfile)
    If fi.Exists Then
        fi.refresh
        Select Case info
            Case Is = "Exists"
                Ret = fi.Exists.ToString
            Case Is = "Delete"
                fi.Delete()
                Ret = fi.Exists.ToString
            Case Is = "Created"
                Ret = fi.CreationTime.ToString("MM/dd/yyyy hh:mm:ss tt")
            Case Is = "Access"
                Ret = fi.LastAccessTime.ToString("MM/dd/yyyy hh:mm:ss tt")
            Case Is = "Mod"
                Ret = fi.LastWriteTime.ToString("MM/dd/yyyy hh:mm:ss tt")
        End Select
    Else
        Ret = "File Not Found"
    End If

    Ret = Ret.Replace(vbCrLf, "")
    Ret = Ret.Replace(vbCr, "")

    Return Ret

End Function

(我也试过使用 File 而不是 FileInfo ...查看帖子历史记录)

更新
作为测试，我使用 AutoIT3 代码对系统进行了文件检查。它返回了准确的信息。 AutoIT3 检查后，vb.net 返回了准确的时间戳。那么，AutoIT3 做得更好的 vb.net 有什么问题？

Func _timestampchk($path)
Dim $file,$astamp
$file = $path
$astamp = FileGetTime($file, 0, 0)
If IsArray($astamp) Then
    $stamp = $astamp[1] & "/" & $astamp[2] & "/" & $astamp[0] & " " & $astamp[3] & ":" & $astamp[4]
ElseIf $astamp = 0 Then
    $stamp = "File " & $path & " not Found"
Else
    $stamp = 0
EndIf
Return $stamp
EndFunc   ;==>_timestampchk

Answer 1

尝试 FileSystem.GetFileInfo ，正如 Andrew Morton 和 neoistheone 所指出的

Dim information = My.Computer.FileSystem.GetFileInfo("C:\MyLogFile.log")
information.Refresh()   ' Calls must be made to Refresh before attempting to get the attribute information, or the information will be outdated.
MsgBox("The file's full name is " & information.FullName & ".")
MsgBox("Last access time is " & information.LastAccessTime & ".")
MsgBox("The length is " & information.Length & ".")

尽管有记录和理由，但这是一种奇怪的行为。
出于好奇，我也会尝试下面的这些代码，看看是否也会出现问题。
尝试使用 Windows API 并查看它是否仍然返回“缓存”数据。

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

如果这不能解决，请尝试以编程方式调用 Open Properties 窗口，然后读取日期时间信息，看看是否可以解决问题:

'#VBIDEUtils#***********************************************
' * Programmer Name  : Waty Thierry
' * Web Site         : www.geocities.com/ResearchTriangle/6311/
' * E-Mail           : waty.thierry@usa.net
' * Date             : 28/06/99
' * Time             : 13:16
' ********************************************************
' * Comments         : Showing the Properties dialog box
' *
' * This tip demonstrates how To use the Win32 API To
' * bring up the explorer properties
' * dialog box For a specified file.
' * This API Function has the same effect As Right
' * clicking On a file In Windows 95 And selecting properties.

' **************************************************
Option Explicit On

    Private Type SHELLEXECUTEINFO
        cbSize As Long
        fMask As Long
        hwnd As Long
        lpVerb As String
        lpFile As String
        lpParameters As String
        lpDirectory As String
        nShow As Long
        hInstApp As Long
        lpIDList As Long
        lpClass As String
        hkeyClass As Long
        dwHotKey As Long
        hIcon As Long
        hProcess As Long
    End Type

Private Const SEE_MASK_INVOKEIDLIST = &HC
Private Const SEE_MASK_NOCLOSEPROCESS = &H40
Private Const SEE_MASK_FLAG_NO_UI = &H400

Private Declare Function ShellExecuteEX Lib "shell32.dll" Alias _
   "ShellExecuteEx" (SEI As SHELLEXECUTEINFO) As Long

Public Function ShowProps(FileName As String, _
   OwnerhWnd As Long) As Boolean

    'USAGE:
    'To show the properties dialog box of "c:\autoexec.bat", use the following code:
    'Call ShowProps("c:\autoexec.bat", Me.hwnd)
    'Function will return false if
    'property windows can't be shown for
    'any reason (e.g., invalid file or Ownerhwnd)


    On Error Resume Next
    Dim SEI As SHELLEXECUTEINFO
    Dim r As Long
    With SEI
        .cbSize = Len(SEI)
        .fMask = SEE_MASK_NOCLOSEPROCESS Or _
         SEE_MASK_INVOKEIDLIST Or SEE_MASK_FLAG_NO_UI
        .hwnd = OwnerhWnd
        .lpVerb = "properties"
        .lpFile = FileName
        .lpParameters = vbNullChar
        .lpDirectory = vbNullChar
        .nShow = 0
        .hInstApp = 0
        .lpIDList = 0
    End With
    r = ShellExecuteEX(SEI)
    ShowProps = r
End Function